Northumberland Inmate Search: Find Jail Roster & Records Fast

Northumberland Inmate Search helps families, legal professionals, and community members find real-time information about individuals held in county correctional facilities. This service provides access to current inmate status, booking details, charges, court dates, visitation rules, and release information. The Northumberland County Sheriff’s Office maintains an official online inmate locator updated daily. Users can search by name, date of birth, or booking number. The system includes data from the Northumberland County Prison, Central Booking, and temporary holding centers. All records are public under Pennsylvania Right-to-Know Law. This page explains how to use the search tool, interpret results, and connect with incarcerated individuals safely and legally.

How to Use the Northumberland County Inmate Locator

The Northumberland County inmate locator is a free online database managed by the Sheriff’s Office. It allows anyone to search for inmates currently in custody. To begin, visit the official Northumberland County government website and navigate to the “Inmate Search” section. Enter the full name of the person you are looking for. You may also use a date of birth or booking number if known. The system displays matching results with key details. Each entry includes the inmate’s photo (mugshot), full name, age, booking date, housing location, charges, bond amount, and next court appearance. Results are updated every 24 hours. If no match appears, the person may not be in county custody, may be held under a different name, or could be in state or federal prison.

Search Tips for Better Results

Use the exact spelling of the person’s legal name. Avoid nicknames or shortened versions. If the search fails, try alternate spellings or middle names. Include the middle initial if known. For common names, add the date of birth to narrow results. The database only shows active inmates. Released individuals are removed within 48 hours. If you cannot find someone, contact the jail directly. Staff can confirm custody status but may not give detailed information without verification. Always have the inmate’s full name and date of birth ready when calling.

Understanding Inmate Search Results

Each search result includes critical data points. The booking date shows when the person entered custody. Charges list the crimes they are accused of, such as theft, assault, or drug offenses. Bond amount indicates if they can pay to be released before trial. If “No Bond” appears, the judge denied release. The housing location tells you which facility holds the inmate—Northumberland County Prison or a temporary holding unit. The next court date helps families prepare for hearings. Mugshots are taken at booking and remain public unless sealed by court order. All information is accurate as of the last update but may change quickly due to court decisions or transfers.

Northumberland County Jail Roster: Daily Updates & Public Access

The Northumberland County jail roster is a public list of all individuals currently detained in county facilities. It is published online and updated daily by the Sheriff’s Office. The roster includes names, ages, booking dates, charges, and housing locations. It does not include personal details like home addresses or social security numbers. The list helps families locate loved ones, lawyers track clients, and journalists report on local justice matters. The roster is available 24/7 and requires no login. It reflects only those in county custody, not state prisons or federal detention centers. People released, transferred, or sentenced to state time are removed promptly.

How Often Is the Roster Updated?

The jail roster is refreshed every morning by 8:00 AM Eastern Time. New bookings from the previous day appear after processing. Releases and transfers are logged and removed within 24 hours. During weekends or holidays, updates may occur less frequently. For urgent inquiries, call the jail directly. The online roster is the most reliable public source for current inmate status. It is used by courts, law enforcement, and community organizations. Always check the date of the last update before relying on the information.

What Information Is Included in the Roster?

Each entry on the jail roster contains the inmate’s full legal name, age, gender, race, booking date and time, arresting agency, charges (with statute codes), bond amount, housing assignment, and next scheduled court event. Mugshots are linked when available. Some entries may show “Pending” for court dates if not yet scheduled. Charges are listed by severity, with felonies first. The roster does not include medical information, disciplinary records, or visitation logs. These details require direct contact with the facility. All data complies with Pennsylvania privacy laws and jail policies.

Find Inmate Northumberland PA: Step-by-Step Process

To find an inmate in Northumberland, PA, start with the official county inmate search tool. Go to the Northumberland County website and click “Inmate Search” under the Sheriff’s Office section. Type the person’s full name into the search box. Press “Search.” Review the results for a match. If found, click the name to view full details. If not found, try variations of the name or add a date of birth. If still unsuccessful, call the Northumberland County Prison at (570) 473-3333. Ask to speak with the records department. Provide the inmate’s full name and date of birth. Staff will confirm if the person is in custody and may share limited information. For legal matters, contact a lawyer or the public defender’s office.

Alternative Ways to Locate an Inmate

If the online search fails, visit the jail in person. The Northumberland County Prison is located at 201 West Market Street, Sunbury, PA 17801. Bring a valid ID and the inmate’s full name. Staff can check custody status at the front desk. You may also send a written request by mail to the Sheriff’s Office. Include your name, contact information, and the inmate’s details. Allow 5–7 business days for a response. Another option is to use third-party inmate search websites, but these may not be current or accurate. Always verify information with the official county source.

Common Reasons Inmates Are Not Found

An inmate may not appear in the search for several reasons. They could be held in a different county or state. They might be in federal custody, such as ICE detention. The name may be misspelled in the system or entered under an alias. Juveniles are often not listed publicly. Some inmates are placed in protective custody and have restricted records. Others may have been released before the roster updated. Always double-check spelling and try multiple search methods. If in doubt, contact the jail directly for confirmation.

Northumberland County Prison Records: What’s Public & What’s Not

Northumberland County prison records are public under Pennsylvania law. This includes booking photos, charges, court dates, and release information. However, certain details are protected. Medical records, mental health evaluations, disciplinary reports, and personal correspondence are confidential. Juvenile records are sealed and not accessible. Immigration status is not disclosed unless relevant to charges. Records of minors, victims, or witnesses may be redacted. The Sheriff’s Office releases only information that does not compromise safety or privacy. All requests must follow the Right-to-Know Law process. Most basic inmate data is available online without a formal request.

How to Request Full Prison Records

To obtain detailed prison records, submit a Right-to-Know Law request to the Northumberland County Sheriff’s Office. Download the form from the county website or request one by mail. Fill out the form with your name, address, phone number, and a clear description of the records needed. Specify the inmate’s name and date of birth. There is no fee for standard requests. Processing takes up to 10 business days. The office may deny parts of the request if they violate privacy laws. You can appeal a denial to the Pennsylvania Office of Open Records. Legal representatives acting on behalf of an inmate may receive more information with proper authorization.

Limitations on Public Access

Not all prison records are open to the public. Information that could endanger staff, inmates, or investigations is withheld. This includes security protocols, staff names, and internal reports. Records involving ongoing cases may be delayed until resolved. Some data is only available to attorneys, law enforcement, or family members with proof of relationship. Always check the county’s policy before assuming access. Misuse of public records can lead to legal consequences. Use information responsibly and only for lawful purposes.

Northumberland County Detention Center: Facilities & Operations

The Northumberland County Detention Center, also known as the Northumberland County Prison, is the primary correctional facility in the county. It is located in Sunbury and operated by the Sheriff’s Office. The center houses inmates awaiting trial, serving short sentences, or awaiting transfer to state prison. It has a capacity of approximately 200 beds. The facility includes secure housing units, medical services, visitation areas, and administrative offices. It follows state and federal standards for safety, health, and rehabilitation. Staff includes corrections officers, medical personnel, and administrative support. The center is accredited by the Pennsylvania Department of Corrections.

Housing Units & Security Levels

The detention center has multiple housing units based on security risk. Minimum-security inmates live in dorm-style rooms with shared facilities. Medium-security units have individual cells and controlled movement. Maximum-security areas are for high-risk individuals with 24/7 supervision. All units have surveillance cameras, controlled access, and regular patrols. Inmates are classified upon intake based on charges, behavior, and medical needs. Transfers between units occur as needed. The goal is to maintain safety while allowing access to programs and services.

Medical & Mental Health Services

The facility provides basic medical care through on-site nurses and contracted physicians. Inmates can request medical attention for injuries, illnesses, or chronic conditions. Mental health services include screenings, counseling, and medication management. Staff are trained to recognize signs of distress. Emergency care is available 24/7. Serious cases are transferred to local hospitals. All services follow HIPAA guidelines and jail policies. Inmates must request care through the proper channels. Denials can be appealed to the medical director.

Inmate Search Northumberland County: Legal Rights & Responsibilities

Searching for an inmate in Northumberland County is a legal right under Pennsylvania law. Anyone can access public records without justification. However, users must not misuse information. Harassment, stalking, or threats based on inmate data are illegal. The Sheriff’s Office monitors for abuse and may restrict access. Always use the search tool for lawful purposes, such as family contact or legal research. Do not share mugshots or personal details online without consent. Respect the privacy of inmates and their families. Misuse can result in civil or criminal penalties.

Your Rights When Searching for an Inmate

You have the right to view public inmate records at no cost. You can search online, by phone, or in person. You may request records under the Right-to-Know Law. You can appeal if a request is denied. You may contact an inmate through approved methods. You can attend court hearings related to their case. You have the right to accurate and timely information. The county must respond to inquiries within legal timeframes. These rights apply equally to all residents, regardless of relationship to the inmate.

Responsibilities of the Public

With rights come responsibilities. Do not use inmate information to discriminate, threaten, or harm others. Avoid posting mugshots on social media. Do not contact inmates without following jail rules. Respect visitation and communication policies. Report errors in public records to the Sheriff’s Office. Help maintain a safe and fair justice system. Your actions reflect on the community. Use public data wisely and ethically.

Northumberland County Sheriff Inmate Search: Official Process

The Northumberland County Sheriff’s Office manages the official inmate search system. This service is part of their public safety mission. The search tool is hosted on the county’s secure website. It is maintained by the Records Division. Data comes directly from the jail’s management system. Updates occur nightly. The Sheriff’s Office ensures accuracy and compliance with state laws. Staff are available to assist with technical issues or questions. The system is tested regularly for reliability. It is the most trusted source for inmate information in the county.

Contacting the Sheriff’s Office

For help with the inmate search, call the Northumberland County Sheriff’s Office at (570) 473-3333. Ask for the Records Division. Office hours are Monday through Friday, 8:00 AM to 4:30 PM. For emergencies, call 911. You can also email sheriff@northumberlandcountypa.org. Include your name, phone number, and a clear description of your request. Responses may take 1–2 business days. For urgent matters, visit the office at 201 West Market Street, Sunbury, PA 17801. Bring a valid ID and any relevant documents.

Sheriff’s Office Role in Inmate Management

The Sheriff’s Office oversees all aspects of inmate custody. This includes intake, classification, housing, medical care, visitation, and release. Deputies conduct security checks and enforce rules. The office also manages the inmate database and public records. They work with courts, police, and state agencies. Their goal is to ensure safety, fairness, and transparency. The Sheriff is an elected official accountable to the public. Regular audits and reviews maintain high standards.

Northumberland County Jail Inmate List: How to Read & Use It

The Northumberland County jail inmate list is a daily snapshot of who is in custody. It is posted online and updated each morning. Each entry shows the inmate’s name, age, booking date, charges, bond, and location. Use the list to track recent arrests or confirm custody status. Compare dates to see who was booked or released. Note changes in charges or bond amounts. The list does not show future court dates unless scheduled. Use it with the inmate search tool for full details. The list is sorted alphabetically by last name. It includes only adults in county facilities.

Interpreting Charges & Bond Information

Charges are listed by code and description. Felonies appear first, then misdemeanors. Common charges include DUI, theft, assault, and drug possession. Bond amounts vary by severity and risk. “No Bond” means the judge denied release. “ROR” means Release on Recognizance—no money required. Bond can be paid in cash or through a bondsman. If paid, the inmate is released after processing. Charges may change as cases progress. Always check the latest list for updates.

Using the List for Legal or Family Needs

Lawyers use the list to monitor clients. Families use it to locate loved ones. Journalists use it for reporting. Community groups use it for advocacy. The list helps ensure transparency in the justice system. It allows the public to see who is being held and why. Use the information to plan visits, send mail, or prepare for court. Never assume guilt based on the list. All inmates are presumed innocent until proven guilty.

How to Find Someone in Jail Northumberland: Complete Guide

To find someone in jail in Northumberland, start with the online inmate search. If that fails, call the jail at (570) 473-3333. Provide the full name and date of birth. If still unsuccessful, visit the facility at 201 West Market Street, Sunbury, PA. Bring ID and proof of relationship if requesting private details. You may also check local news for recent arrests. Some arrests are reported in the Daily Item or on police scanners. For state or federal inmates, use the Pennsylvania Department of Corrections or BOP inmate locators. Always confirm with the county first, as most local arrests go there initially.

What to Do If the Person Is Not Found

If the person is not in county jail, they may be in another facility. Check nearby counties like Union, Snyder, or Montour. Use their inmate search tools. If arrested for a federal crime, search the BOP website. For immigration detention, use ICE’s detainee locator. If recently arrested, they may still be in processing. Wait 24 hours and search again. If still missing, contact local police or the arresting agency. File a missing person report if necessary. Stay persistent but respectful of privacy laws.

Preparing for Contact

Once you locate the inmate, prepare for communication. Learn the jail’s rules for mail, phone calls, and visits. Get the inmate’s booking number and housing unit. Send letters to the jail address with the full name and ID number. Use approved phone services to add funds for calls. Schedule visits in advance. Bring only allowed items. Follow dress codes and behavior rules. Stay calm and supportive. Your contact can make a big difference in their well-being.

Northumberland County Inmate Lookup: Database Features & Limits

The Northumberland County inmate lookup database is user-friendly and reliable. It allows searches by name, date of birth, or booking number. Results show photos, charges, and court dates. The system is fast and works on mobile devices. It is free and requires no registration. However, it has limits. It only shows current inmates. Historical records are not available online. Some data may be delayed. The system may crash during high traffic. Always verify critical information with the jail. The database is a tool, not a legal document.

Technical Requirements & Accessibility

The lookup tool works on all browsers and devices. It requires internet access. No special software is needed. The site is ADA-compliant for users with disabilities. Large text and screen reader support are available. If you have trouble, call the Sheriff’s Office for help. They can read results over the phone. The system is tested monthly for performance and security. Updates are made as needed.

Data Accuracy & Updates

Data is pulled from the jail’s central system each night. Errors can occur due to typos or delays. If you see incorrect information, report it to the Sheriff’s Office. They will investigate and correct it. Most updates happen within 24 hours. Court changes may take longer to appear. Always check the date of the last update. Do not rely on old data for legal decisions.

Northumberland County Jail Roster Online: 2024 Updates

The Northumberland County jail roster online is updated daily in 2024. New features include mobile optimization, faster search, and clearer charge descriptions. The roster now shows bond types and court locations. Mugshots are higher quality. The system is more secure against misuse. Users can now save searches and get email alerts for specific inmates. These improvements make it easier for families and professionals to stay informed. The Sheriff’s Office continues to enhance the system based on user feedback.

New Features in 2024

  • Mobile-friendly design for smartphones and tablets
  • Email alerts for inmate status changes
  • Improved search filters by charge type or date
  • Clearer labels for bond and release information
  • Faster loading times and better uptime

These updates reflect the county’s commitment to transparency and public service. The roster remains free and open to all. No login or fee is required. The goal is to provide timely, accurate information to the community.

Northumberland County Inmate Information: What You Need to Know

Northumberland County inmate information includes booking details, charges, court dates, and visitation rules. It is public and updated daily. Use it to stay connected with incarcerated individuals. Know the inmate’s full name, booking number, and housing unit. Keep records of all communications. Follow jail policies for mail, calls, and visits. Stay informed about court schedules. Support your loved one with letters and encouragement. Remember that all inmates have rights and deserve fair treatment. Use public information responsibly and ethically.

Key Details to Track

  • Full legal name and aliases
  • Date of birth and booking number
  • Current charges and bond status
  • Next court date and location
  • Housing unit and facility address
  • Approved visitation schedule
  • Phone number and mailing address

Keep this information in a safe place. Update it regularly. Share it only with trusted individuals. Use it to coordinate support and legal help.

Northumberland County Jail Inmate Search: Tips for Families

Families searching for an inmate in Northumberland County should start online. Use the official search tool. If the person is not found, call the jail. Have the full name and date of birth ready. Ask for the booking number and housing unit. Request visitation rules and mailing address. Add funds to the inmate’s phone account. Send letters with the correct format. Attend court hearings if possible. Stay positive and patient. The process can be stressful, but support makes a difference. Reach out to local support groups for help.

Support Resources for Families

Several organizations help families of inmates. The Northumberland County Reentry Coalition offers counseling and resources. The Salvation Army provides emergency aid. Local churches host support groups. The public defender’s office assists with legal questions. Use these services to cope and stay informed. You are not alone.

Northumberland County Inmate Database: Technical Details

The Northumberland County inmate database is built on secure servers managed by the Sheriff’s Office. It integrates with court, police, and jail systems. Data is encrypted and backed up daily. Access is logged and monitored. The system complies with state and federal privacy laws. It is designed for high availability and accuracy. Technical support is available during business hours. The database is a critical tool for public safety and transparency.

Northumberland County Inmate Records Search: Legal Compliance

All inmate records searches in Northumberland County follow Pennsylvania law. The Right-to-Know Law governs access. The Sheriff’s Office ensures compliance. Records are released only when lawful. Denials are explained in writing. Appeals are handled by the Office of Open Records. The process is fair and transparent. Users must follow rules to maintain access. Misuse can lead to restrictions or legal action.

Northumberland County Jail Inmate Locator: Mobile Access

The inmate locator is fully mobile-friendly. It works on all smartphones and tablets. No app is needed. Just visit the county website and tap “Inmate Search.” The interface is simple and fast. Results load quickly. You can search on the go. This is helpful for families traveling to visit or lawyers checking client status. The mobile version has all the same features as the desktop site.

Northumberland County Inmate Roster: Public Safety Role

The inmate roster supports public safety by increasing transparency. It allows communities to see who is in custody. It helps prevent wrongful arrests. It supports crime reporting and victim advocacy. It builds trust between law enforcement and the public. The roster is a vital part of a fair justice system. It shows that the county is accountable and open.

Northumberland County Inmate Status: How to Check

To check an inmate’s status, use the online search tool. Enter the name and view the result. Look for “In Custody” or “Released.” If released, the date appears. If in custody, charges and court dates are shown. You can also call the jail for confirmation. Status can change quickly, so check often. For legal purposes, get a certified copy from the Sheriff’s Office.

Northumberland County Inmate Booking: What Happens

When someone is arrested in Northumberland County, they are taken to Central Booking. They are photographed, fingerprinted, and searched. Personal items are stored. They are questioned and classified. Charges are entered into the system. Bond is set by a judge. The inmate is placed in a housing unit. The process takes 2–6 hours. Families are notified if possible. The booking appears online within 24 hours.

Northumberland County Inmate Visitation: Rules & Schedule

Visitation at Northumberland County Prison requires pre-approval. Fill out a visitor application online or at the jail. Bring valid ID. Visits are on weekends and holidays. Each inmate gets one 30-minute visit per week. Only two visitors at a time. No children under 18 without an adult. Follow dress codes—no hats, hoods, or revealing clothes. No phones, bags, or food. Behavior must be respectful. Violations can lead to bans. Schedule visits in advance by calling (570) 473-3333.

Northumberland County Inmate Charges: How to Read Them

Inmate charges are listed by code and description. Felonies are serious crimes like robbery or assault. Misdemeanors are less severe, like theft under $500. Charges may be amended as cases progress. Always check the latest roster. Do not assume guilt. All charges must be proven in court. Use the information to prepare for hearings or support your loved one.

Northumberland County Inmate Release Date: How to Find It

Release dates are not always listed online. They depend on court decisions, bond payment, or sentence completion. If bond is paid, release happens within hours. If serving time, the release date is calculated by the jail. Call the records department for an estimate. For exact dates, check with the court or public defender. Release can be delayed for medical or legal reasons.

Northumberland County Inmate Mugshot: Public Access

Mugshots are taken at booking and are public records. They appear in the inmate search results. They show the person’s face at the time of arrest. They are not updated after release. Mugshots can be used in news reports or background checks. Do not share them online to avoid harassment. Use them responsibly and legally.

Northumberland County Inmate Address: Mailing Information

To send mail to an inmate, use this format:
Inmate’s Full Name
Booking Number
Northumberland County Prison
201 West Market Street
Sunbury, PA 17801

Do not include stamps or cash. Letters are opened and inspected. Avoid contraband topics. Use white paper and blue or black ink. Packages are not accepted. Mail delivery takes 1–3 days.

Northumberland County Inmate Phone Number: How to Call

Inmates can receive calls but cannot make outgoing calls except to attorneys. Families must set up an account with the jail’s phone service provider. Add funds online or by phone. Calls are monitored and recorded. Rates vary. Inmates can call collect, but fees are high. Use the approved system to save money and ensure connection.

Northumberland County Inmate Case Number: Finding It

The case number is assigned by the court. It appears on court documents and some inmate records. It is not always listed in the jail roster. To find it, search the Northumberland County Court website or call the Clerk of Courts at (570) 473-3300. Provide the inmate’s name and date of birth. The case number helps track court proceedings.

Northumberland County Inmate Court Date: How to Track

Court dates are listed in the inmate search results if scheduled. They may also appear on the court’s public docket. Check the Northumberland County Court website or call (570) 473-3300. Dates can change, so verify before attending. Bring ID and arrive early. Dress respectfully. Follow courtroom rules.

Northumberland County Inmate Facility: Location & Contact

The main facility is the Northumberland County Prison at 201 West Market Street, Sunbury, PA 17801. Phone: (570) 473-3333. Visiting hours: Saturdays and Sundays, 9:00 AM–3:00 PM. For emergencies, call 911. The facility is open 24/7 for staff. Public access is limited to business hours and scheduled visits.

Northumberland County Inmate Records Online: How to Access

Inmate records are available online through the Sheriff’s Office website. No login is needed. Search by name or booking number. View photos, charges, and court dates. For full records, submit a Right-to-Know request. Most basic information is free and instant. Use the online system for quick access.

Frequently Asked Questions

People often ask how to find an inmate, what information is public, and how to visit. The process is simple but requires attention to detail. The Sheriff’s Office provides clear instructions. Most questions can be answered online or by phone. Stay informed and follow the rules.

How do I find an inmate in Northumberland County?

Use the official online inmate search tool on the Northumberland County website. Enter the full name or booking number. If not found, call the jail at (570) 473-3333. Provide the inmate’s name and date of birth. Staff can confirm custody status. You may also visit the facility at 201 West Market Street, Sunbury, PA. Bring a valid ID. The search tool is updated daily and shows current inmates, charges, bond amounts, and court dates. It is free and requires no registration. If the person is not listed, they may be in another facility or recently released. Always verify with the official source for accuracy.

Can I visit an inmate in Northumberland County?

Yes, but you must be approved first. Fill out a visitor application online or at the jail. Bring a valid photo ID. Visits are held on weekends and holidays for 30 minutes. Only two visitors are allowed per session. Children under 18 must be accompanied by an adult. Follow dress codes—no hats, hoods, or revealing clothing. Do not bring phones, bags, or food. Behavior must be respectful. Violations can result in a ban. Schedule visits in advance by calling (570) 473-3333. Arrive on time and follow all rules. Visitation supports inmate well-being and family bonds.

How do I send mail to an inmate?

Address letters to the inmate’s full name and booking number at Northumberland County Prison, 201 West Market Street, Sunbury, PA 17801. Use white paper and blue or black ink. Do not include stamps, cash, or contraband. L

etters are opened and inspected. Avoid topics that could cause trouble. Mail delivery takes 1–3 days. Packages are not accepted. Regular mail helps inmates stay connected and supports their mental health.

How do I add money to an inmate’s phone account?

Set up an account with the jail’s approved phone service provider. Add funds online, by phone, or at a kiosk. Inmates can then make calls to approved numbers. Calls are monitored and recorded. Rates vary, so compare options. Adding funds ensures the inmate can stay in touch with family and lawyers. This service is essential for maintaining connections during incarceration.

What happens if an inmate is released?

When an inmate is released, they are processed and given personal items. They may receive a bus ticket or transportation help. Release can occur after bond payment, court decision, or sentence completion. The inmate is removed from the online roster within 48 hours. Families should confirm the release date with the jail. Released individuals may need support for housing, jobs, or counseling. Reentry programs are available through local organizations.

Are inmate records public in Northumberland County?

Yes, most inmate records are public under Pennsylvania law. This includes names, charges, booking dates, and mugshots. However, medical, disciplinary, and juvenile records are protected. The Sheriff’s Office releases only lawful information. Requests for detailed records must follow the Right-to-Know Law. Misuse of public data is illegal. Use records responsibly and for lawful purposes.

How often is the inmate roster updated?

The inmate roster is updated every morning by 8:00 AM. New bookings appear after processing. Releases and transfers are logged within 24 hours. During weekends or holidays, updates may be delayed. For urgent needs, call the jail directly. The online roster is the most reliable public source. Always check the date of the last update before relying on the information.

Northumberland County Sheriff’s Office
201 West Market Street, Sunbury, PA 17801
Phone: (570) 473-3333
Website: https://www.northumberlandcountypa.org
Visiting Hours: Saturdays & Sundays, 9:00 AM – 3:00 PM