Mercer County Jail (MCCC): What to Do After an Arrest

Many families are surprised to learn that the Mercer County jail is not in Trenton. The Mercer County Correction Center (MCCC) sits on Route 29 in Hopewell Township, along the Delaware River, north of the city. Anyone arrested in Mercer County on a complaint-warrant, from Princeton to Hamilton to Hightstown, ends up there while waiting for a judge.

This page covers what families need to know in the first days: how the facility works, how visits and packages are handled, and how to get your loved one in front of a judge with a plan for release.

Mercer County Correction Center Facts

Facility	Mercer County Correction Center (MCCC)
Location	1750 River Road (Route 29 North), Hopewell Township, NJ
Phone	(609) 397-7460
Capacity	Bed space for 871 men and women at minimum, medium and maximum security
Population	Pretrial detainees, people serving county sentences of up to 364 days, and state-sentenced inmates awaiting transfer to state prison
Court	Criminal Courthouse, 400 South Warren Street, Trenton
Our nearest office	100 Horizon Center Boulevard, Hamilton, NJ 08691 · (732) 858-6959

If someone you love was just taken to the MCCC, call (732) 858-6959. A first appearance has to happen within 48 hours, and preparation starts now.

Most People Do Not Stay Long

Under New Jersey’s bail reform law, a judge must hold a first appearance within 48 hours of a person’s commitment to the jail. Most defendants are released on conditions, not money bail. Defendants usually appear by video from the Correction Center. The exception is when the Mercer County Prosecutor’s Office files a motion for pretrial detention. Then a detention hearing is scheduled, and the person stays at the MCCC until it is decided.

Fewer People Are Held in Mercer County Than a Decade Ago

Bail reform changed the Correction Center’s population dramatically. On December 31, 2015, Mercer County held 564 people in jail awaiting trial. By December 31, 2024, that number was 234, a drop of 58.5 percent. The decline continued in 2024 alone, when the pretrial population fell 34.6 percent from the year before.

Mercer County nonsentenced pretrial jail population on December 31 of each year. Source: NJ Courts, Criminal Justice Reform Statistics.

What this means for families: when someone is held at the MCCC today, it is usually for one of three reasons. The prosecutor filed a detention motion that has not yet been heard, a judge granted detention, or the person is serving a sentence or being held on a warrant from another jurisdiction. Knowing which applies tells you what to do next.

The First Hours at the MCCC

After arrest, local police process the charges and transport the person to Hopewell Township. Intake includes identification, a property inventory, medical and mental health screening, and a classification that determines housing. During this time:

Phone access may be limited until intake is complete.
Personal property, including phones, wallets and keys, is inventoried and held.
Medical needs should be disclosed at screening. The MCCC provides medical, mental health and social services.

The Path From Arrest to Release

Typical path after an arrest in Mercer County. Facility rules can change; call ahead.

Health, Medication and Mental Health Needs

Medical and mental health issues are common among people in county jails, and they can be urgent in the first days of custody. The MCCC provides medical, mental health and social services, and screening happens at intake. Families can help by:

Telling the defense lawyer about prescriptions, diagnoses and recent hospitalizations, so the information can be raised with the facility and the court
Gathering pharmacy records or a doctor’s letter, which can also support a release plan
Reporting withdrawal risks, such as opioid or alcohol dependence, which can be dangerous if not managed

A documented treatment plan, such as an intake appointment at a program in Trenton or Hamilton, can also be one of the strongest arguments for release at a first appearance.

Visiting Someone at the Mercer County Correction Center

According to Mercer County’s posted visiting rules:

Visits are screened. Visits happen in a screened area, and contact visits are not permitted. The Warden or a designee may approve special visits.
The visitor list is set at admission. Each inmate lists approved visitors, with name, address, phone number and relationship.
Two visitors at a time, up to one hour. Visitors 17 and under (other than a spouse) must be with a parent or guardian.
Bring valid ID. A driver’s license, state ID, passport, employment ID or school ID is accepted. Lack of ID is grounds to refuse a visit.
Visit days depend on housing. Visits run throughout the week and weekend, but the schedule depends on the person’s living unit. Ask your loved one, or call the facility.
Dress code. No orange clothing, sleeveless shirts, spandex, short shorts, mini-skirts, sheer or low-cut clothing, pajama pants, sweaters, coats, jackets, hats or scarves.
Former inmates may not visit for one year after their release.
Searches. Visitors are pat-frisked. Bags, toys and baby carriers are not allowed in the visiting area.

Rules change, so call (609) 397-7460 before making the trip.

Packages, Money and Phone Calls

The MCCC uses the Access Securepak program for packages. Families order approved items through the program instead of mailing them directly, which keeps out contraband. Registration is done through Access Catalog’s New Jersey county package site. For money deposits and phone accounts, ask the facility which vendors it currently uses, since these contracts change.

A critical warning: calls from the MCCC are recorded. Prosecutors routinely review jail calls and use them as evidence. Your loved one should not discuss the facts of the case with anyone except their lawyer.

Attorney Visits and Legal Calls

Conversations between a defendant and a lawyer are confidential, but regular jail phone lines are not. Defense attorneys arrange legal visits and calls through the facility so they can talk privately with clients. Before a first appearance or a detention hearing, a short legal call is often enough to confirm the facts needed for a release argument, such as the client’s address, work schedule, health issues and prior court history.

Holds, Detainers and Warrants From Other Courts

Sometimes a person stays at the MCCC even after a Mercer County judge orders release. The usual reason is a “hold” or detainer from another court. Common examples include:

A municipal court bench warrant from another town, often with its own bail amount
A warrant from another New Jersey county, which may lead to a transfer to that county’s jail
A Pennsylvania or other out-of-state warrant, which can lead to extradition proceedings
A violation of probation or parole detainer

Each hold has to be resolved separately. A defense lawyer can identify every open warrant at the start, contact the other courts, and try to resolve them together so that a release order in Trenton actually means your family member comes home. Clearing old municipal warrants before a first appearance can also make the release argument stronger, because it shows the judge the person is taking responsibility for every open matter.

Serving a Sentence at the MCCC

People sentenced to county time of 364 days or less, by a municipal or Superior Court judge, typically serve it at the MCCC. Eligible inmates may take part in educational programs, and some minimum-security inmates work on supervised details such as grounds maintenance at county facilities. Courts can also order participation in the Superintendent Labor Assistance Program (SLAP), a community service alternative.

What Families Can Do Today

Confirm where the person is held and the charges, including the arresting department.
Call a defense lawyer before the first appearance.
Gather release documents: proof of address, employment letters, school enrollment and medical or treatment records.
Plan transportation. Releases happen at the Hopewell Township facility, not in Trenton.
Keep phone conversations and messages free of any discussion of the case.

Frequently Asked Questions

Is there a cash bail amount I can pay?

Usually not. Most release decisions now involve conditions, not money. When monetary bail is set, the court and the facility can explain how to post it.

My family member lives in Pennsylvania. Can they go home if released?

Often, yes. Release conditions may include reporting to Pretrial Services by phone. Out-of-state travel limits depend on the judge’s order.

Can a lawyer visit before the first appearance?

Yes. Attorneys can arrange legal visits and calls at the MCCC, which helps build a release plan before the hearing.

How do I find out why someone is still being held?

Ask the defense attorney to check the court record. The most common reasons are a pending detention motion, a detention order, a sentence, or a hold from another county or state.

Can I drop off clothes for court?

Facility policies on court clothing vary. Call the Correction Center at (609) 397-7460 or ask the defense attorney how to arrange it.

Help for Families of People Held in Mercer County

Keith Oliver, William Proetta and Brett Rosen represent people held at the Mercer County Correction Center and appear at their hearings in Trenton. Call (732) 858-6959 or contact us online. If the arrest came from an old case, see warrants in Mercer County.

Mercer County Jail: What to Do After an Arrest