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Jason A Seidman

Criminal defense Attorney at New Brunswick, NJ

4.7   25 reviews
  • Licensed for 14 years
    State NJ
    Acquired 2009
    Active No misconduct found

We have not found any instances of professional misconduct for this lawyer.

About Jason

Learn Jason’s areas of practice.

Practice areas
  1. Criminal defense
    Aggressive former prosecutor

    14 years, 500 cases

  2. DUI and DWI
    Speeding & Traffic

    14 years, 250 cases

Jason A. Seidman spent five years as a prosecutor and attorney for the Middlesex County Prosecutor’s office, attaining a level of know-how that is invaluable to his criminal defense practice — and his clients — today.

“I know how prosecutors think,” he says. “That can be incredibly valuable now, in either trying to get a better plea offer or in trying to find a strategy to win at trial because you know that the prosecutor is thinking like a prosecutor and you can slip some defense attorney strategies in there that they never see coming.”

Mr. Seidman’s current practice focuses on criminal law with a strong emphasis on felony-level cases. He has achieved numerous positive outcomes for clients, including dismissal of a case where his client faced up to 10 years in prison involving a gun that the client didn’t know was in his bag and was detected by airport screening. Mr. Seidman has also been successful at having a number of his clients who were first-time offenders admitted to the state’s Pretrial Intervention Program.

During his time with the Middlesex County Prosecutor’s office, Mr. Seidman had some high-profile achievements. During the first 3½ years of his tenure there, he became a member of the trial team that handled street-level drug-distribution cases in New Brunswick. These cases ranged from possession with intent to distribute marijuana and cocaine all the way up to first-degree distribution and possession with the intent to distribute PCP. In addition to prosecuting drug cases, he also supervised the office’s Drug Court Unit, which aspires to help people beat their habits. He then moved to a trial team that handled all the crimes occurring in Woodbridge Township, Jamesburg, Milltown, Monroe, and Sayreville.

One of the highlights of his days as a prosecutor involved a cold case that was brought back to life by DNA evidence 30 years after the homicide of a 15-year-old prostitute. Mr. Seidman was part of the team that secured the conviction of the killer following a five-week trial that involved 30 witnesses.

Another highlight was his involvement in the investigation and prosecution of a 24-defendant racketeering case involving rival subsets of the Bloods street gang, the G-Shine Bloods and the Nine Trey Bloods, which were engaged in a turf war that resulted in the death of an innocent man killed by a stray bullet.

As that case matured, Mr. Seidman became the legal adviser to the Middlesex County Gangs, Guns and Drugs Task Force, a proactive investigative unit that assists the prosecutors. He spent his last 1½ years in the prosecutor’s office in that capacity.

A New Jersey native, Mr. Seidman comes from a family of lawyers. His mother and grandfather were both prosecutors, and his great-grandfather was a trusts and estates attorney. He received a B.A. in government and law from Lafayette College in 2005 and earned his J.D. from the University of the District of Columbia in 2009.

Asked what he likes most about his work, Mr. Seidman says he simply loves all aspects of litigation. “I like finding issues in cases. I like finding the one spot that nobody else sees and using that to my advantage. I like the competition, the back and forth, but I tend to do it in a subdued way. I’m not a very aggressive guy until I have to be.”

He considers his greatest strength as an attorney to be the level of preparation he invests in all his cases.

“I do not like to be surprised,” he says. “I do not like to lose.”

Photos and videos


Law Offices of Jonathan F. Marshall
53 Paterson Street
1st Floor (by appointment only)
New Brunswick, NJ, 08901

Criminal Defense lawyers nearby


4.7 / 5.0
  25 customer reviews
Posted by anonymous | April 27, 2023
This review is from a person who hired this attorney.
| Hired Attorney
The best attorney
I was represented by the best lawyer in NJ Mr.Seidman, he's not just an ordinary lawyer but smart and was able to resolve all issues and fought on my behalf to avoid jail time. No words could express our heartfelt gratitude and appreciation for the outcome of the case. God bless you and your team!
Posted by ——- | February 20, 2023
This review is from a person who hired this attorney.
| Hired Attorney
Great lawyer
MR Seidman is a very good lawyer I was fighting a gun charge out of Dunellen the gun was clearly mines and the gun was found my Dunellen Police the case was dismissed never reached grand jury case was dismissed after a month. Who ever stay that Jason is a mad lawyer you crazy he proved the evidence they had on me Jason get all my charges dismissed.
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Posted by Al | November 9, 2020
This review is from a person who hired this attorney.
| Hired Attorney
Best attorney
Let me start off by telling you Jason is not your typical lawyer liar. Jason is actually an attorney who cares. He puts effort in his work and also takes the time out to speak to you without saying you owe him $1000 for a phone call. I’ve dealt with a lot of attorneys in my life as far as getting retired from a city job, As far as getting Social Security disability and Worker’s Comp. They all deserved that title lawyer liar. Not Jason, he did my red flag trial , Why a malicious doctor And his 24 hour on-call bully Lawyer decided to make false claims to have my firearms taken under his new horrible unconstitutional red flag law. Of course Jason won my case and my stuff is back in the safe where it’s been for 10 years not bothering anyone, but just because of a bad review my stuff was taken in an instant unconstitutional law. Not only would I consider Jason a great attorney but I now consider Jason a friend and that is more important than any case, because people like Jason are hard to fine. I’m glad I found him and I am happy That he not only won my case but we caught the other attorney in many lies which now makes a countersuit more important to me. And also give me the ammunition I need for malicious prosecution counter suit. So everyone reading this if you need a great attorney with a great attitude and a heart of gold Jason is the right person. Most get a bad name because of them going to bed at night dreaming of $ I’m not having any compassion , Totally different when you hire Jason. I give Jason five stars and if I can give him 10 he would definitely get that much.
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Posted by Emily | June 5, 2020
This review is from a person who hired this attorney.
| Hired Attorney
You are an absolute amazing lawyer.
Jason, thank you. Seriously, no words could ever express to you how much gratitude, respect, and appreciation I have for you. I hung up, and cried like a baby..not because of what happened but because you had my back that entire time and I would be sent off to prison if it wasn't for you. You don't look or treat me as a criminal and that means so much to me. I respect you to the fullest and never forget how hard you have fought for me for over a year. your amazing. I admire you so much. You have shown me what a real attorney really does, and always asked and made sure how I was doing, and trusted what I had to say to you, always. You made me feel worthy. Not only did you do your job incredibly, you took your time to sit, listen, and talk with me. Thank you for all your hard work and dedication, Jason. You are absolutely amazing.
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Posted by Peter | March 3, 2020
This review is from a person who hired this attorney.
| Hired Attorney
" I need a good Lawyer "! How many of us have had to make that dreadful call. Filled with anxiety and fear of the unknown we desperately reach out for someone to assure us everything will be OK. The receptionist said " you came to the right place we have Great Lawyers! " Your lawyer will be Jason Seidman. Our case was not an easy one as it involved extradition. Information that I needed and what to expect with many "what ifs" were fed back to me immediately by Nelly, Jason's assistant. This type of Spirit to Serve is rare. It meant a lot to me, someone cared. The big day " court day ", Jason demonstrated his real talent! Backing up his experience with the prosecutors and the Judge he was able to completely have my son cleared and freed in record time. Those of you that have gone through this experience can relate to how wonderful a feeling it is. So no need to just settle for just any legal representation when you can have the very best with Jason Seidman of the Jonathan Marshall Firm!
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Posted by anonymous | February 11, 2020
This review is from a person who hired this attorney.
| Hired Attorney
Mr Jason excellent attorney in the county
I am very happy today with your words in court, may God protect you for the Innocent people always Five stars for you the best attorney in the county
Posted by Jay | February 12, 2019
This review is from a person who hired this attorney.
| Hired Attorney
One of the best lawyers!
Jason has been the only one I could come to in my 3-year long case. He has been there every step of the way ever since the beginning. It has been a scary 3 years and I had the possibility of going away to Prison for a long time. Jason got me the best solution possible in my situation. When choosing a lawyer at first it's hard to know whos right, but just know Jason will do his best and fight for you the whole way until the end. You won't regret hiring him!
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Posted by Moghal | January 14, 2019
This review is from a person who hired this attorney.
| Hired Attorney
Went Above and Beyond!!!
Mr. Seidman helped with my matter in a very professional way. He was very informative, knowledgeable and guided me through the process. He was very patient with me and promptly responded to my e-mails and phone calls. I would certainly recommend his services to anyone who needs his area of expertise. Thanks Jason!
Posted by Mr. A | January 14, 2019
This review is from a person who hired this attorney.
| Hired Attorney
Best Advocate
Thank You Jason, Thank you Brett, for fighting my legal battle. I made a mistake that you were able to correct. This mistake could have destroyed my career or worse put me behind bars. Jason believed in me, he was able to separate the meat from the bones and he never gave up on me or my case. I was found not guilty and innocent in the court of law. Thank you Jason! I recommend you to my friends and family.
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Posted by Erik | May 22, 2018
This review is from a person who hired this attorney.
| Hired Attorney
Got the job done.
I was charged with drug possession with the possibility of some serious consequences. They were able to get me and outcome that I was very pleased with. Definitely would recommend.
Posted by Zach | March 2, 2018
This review is from a person who hired this attorney.
| Hired Attorney
Extremely thorough! Amended my case from a felony to an ordinance!
I was referred to Jason through an amazing lawyer I know in Miami. Jason was extremely detail oriented and emotionally involved in the case. He was quick to respond and helped explain everything throughout the process. Jason got my case brought down from an Assault and Robbery to a Disorderly Conduct. I ended up just having to pay a fine for a charge that carries a max of around 10 years. I would recommend Jason to anybody that is looking for legal representation in Middlesex County. Can’t thank him enough!!
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Posted by anonymous | February 27, 2018
This review is from a person who hired this attorney.
| Hired Attorney
Highly recommend! Professional and persevered through our difficult case.
Jason was our lawyer for a very complicated and difficult legal situation. He did an excellent job of explaining things at each step, and staying positive and persevering during some of the harder moments. He used every possible resource to create an outcome that was beyond our expectations. He has our highest recommedation.
Posted by anonymous | February 23, 2018
This review is from a person who hired this attorney.
| Hired Attorney
Highly recommended
The process was long and achieving the outcome we wanted was unlikely. But Jason was able to ultimately do so, while being straight-forward and supportive along the way.
Posted by anonymous | July 20, 2017
This review is from a person who hired this attorney.
| Hired Attorney
Was very helpful did his beat and got the outcome i was hoping for. Worth everyone dollar
Posted by anonymous | July 10, 2017
This review is from a person who hired this attorney.
| Hired Attorney
Attorney review
He helped me obtain a favourable outcome in my case when I didn't even think it was possible. I highly recommend his services.
Posted by Gary | April 27, 2017
This review is from a person who hired this attorney.
| Hired Attorney
This isn't a business based on one gives you a participation trophy in a court of either succeed, or you fail...and choosing the right counsel can make all the difference. Working with Mr. Seidman, I felt like my case was he had skin in the game, whether we won or I wasn't 'just another client'. Certainly, I was pleased with the effort - he was well-prepared, and able to help me focus on putting my best defense forward. I felt like I was given every opportunity to WIN...and win, we did. I would recommend Mr, Seidman to anyone seeking the very best...someone who has got your back, and can both plan and execute strategy, but also a guy who can help you WIN...not just "give it his best shot". I rated him five stars - and you can retain him with confidence that you will, too.
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Posted by Ron S. | April 12, 2017
This review is from a person who hired this attorney.
| Hired Attorney
Jason Helped me Win a long standing case. Victory!
Jason Seidman was instrumental in helping me fight a longstanding case vs The State of NJ. He was very well versed in what was necessary to present, which avenues to take, and ultimately we prevailed victoriously. I am very thankful to having had him in my corner. Highly suggested!
Posted by Moises | January 24, 2017
This review is from a person who hired this attorney.
| Hired Attorney
Traffic Lawyer
Received a 4 point moving violation ticket, while on PDP! I decided to hire this law firm after a free phone consultation. Mr Siedman reviewed my driving history and gave me plenty of probable options. $89 fine and no points ordered the judge!! Excellent Lawyers!! They are definitely my lawyers for the future!!
Posted by anonymous | September 27, 2016
This review is from a person who hired this attorney.
| Hired Attorney
Attention to details and excellent follow up
Mr Seidman looked at our case and studied it well. He then worked with the Prosecutor's office to find specific waivers that were applied to our case. The end result was the least severe charges for our case. This case took over 9 months and we were very happy with the final outcome.
Posted by anonymous | August 21, 2016
This review is from a person who hired this attorney.
| Hired Attorney
Grand Slam
I cannot say enough good things about Jason. I hired Jason's firm to represent me in a case where I was charged with a DUI and careless driving. I faced seven months loss of license, thousands of dollars in fines and a whole parade of other horribles. In the end, the prosecutor agreed to dismiss the DUI charge entirely, I pleaded guilty to careless driving and paid $200 with a short license suspension. Jason was tremendously well prepared. He could recite the tiniest details about my case from off the top of his head. In earlier proceedings, his firm succeeded in having the breathalyzer test suppressed (thrown out), obtained expert reports and subpoenaed other evidence to challenge the field sobriety tests. Jason presented all of this to the Prosecutor and was able to convince him to dismiss the DUI charge entirely. He also had the experience, skill and background before the Judge so that I wound up with an even shorter suspension than what the Prosecutor recommended. Indeed, the day after my arrest, things looked really bleak; but by the final night in court, Jason and his firm did such a good job that I had a strong chance of beating all the charges had I chosen to go to trial. Jason is a very smart guy with great relationships with the prosecutor and judges. He also worked very hard and knew every aspect of my case. He is also a really good guy, explains things well, and has great common sense. I owe him a tremendous amount of thanks, and this great recommendation.
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  • Free Consultation 30 minutes
  • Retainer Always
Payment methods
Cash, Check, Credit Card


AVVO RATING 8.7 (Excellent)

Work Experience

  • Managing Attorney
  • Law Offices of Jonathan F. Marshall
  • 2018 - Present
  • Attorney
  • The Law Offices of Jonathan F. Marshall
  • 2015 - 2018
  • Assistant Prosecutor/Attorney
  • Middlesex County Prosecutor's Office, New Brunswick, New Jersey
  • 2010 - 2015
  • Managing Attorney
  • Law Office of Jason A. Seidman
  • 2009 - 2010
  • Summer Associate
  • Central Jersey Legal Services
  • 2008 - 2008
  • Summer Associate
  • Arseneault, Whipple, Farmer, Fasset, & Azzarello
  • 2007 - 2007
View all work experience


  • University of the District of Columbia, David A. Clarke School of Law
  • JD - Juris Doctor
  • 2009
  • Lafayette College
  • BA - Bachelor of Arts
  • 2005

Sample of Legal Cases

  • I.M.R. v. A.R.S.
  • The decision of the Family Part was reversed and the Final Restraining Order was vacated.
  • State v. VK
  • All Charges Dismissed
  • State v. BC
  • Not guilty verdict.
View all legal cases


  • Middlesex County Bar Association
  • Member
  • 2013 - Present
  • Middlesex County Prosecutor's Association
  • Member
  • 2011 - 2015

Languages Spoken

  • English
  • Spanish

Honors and Awards

  • Certificate of Completion Drug Court Conference and Training
  • Administrative Office of the Courts
  • 2013
  • Certificate of Completion Top Gun Narcotics Training
  • New Jersey Division of Criminal Justice
  • 2013
  • Certificate of Completion- The Art and Skill of Trial Advocacay
  • Attorney General's Advocacy Institute
  • 2011

Speaking Engagements

  • Expunging a Criminal Record - what you need to know as a defense attorney; what you need to know as a prosecutor
  • Expungement
  • 2015
  • Grand Jury Practice
  • Grand Jury
  • 2014
  • Recent Developments in Expungement Law
  • Expungements
  • 2013
View all speaking engagements

Attorney endorsements

Received (12)
Given (10)
Endorse Jason
Criminal defense Attorney | Apr 28
Relationship: Fellow lawyer in community
"I endorse this lawyer. Jason is a zealous advocate for his clients, is a highly skilled attorney, and is a valuable asset to his law firm and to the practice of law."
Criminal defense Attorney | Jul 12
Relationship: Opposing Counsel on matter
"Jason is a great attorney. As a former prosecutor, he is prepared to represent his clients. He is knowledgeable and ready for any challenge. I endorse him 100 percent."
Criminal defense Attorney | Mar 20
Relationship: Co-worker
"I endorse this lawyer. Jason is very knowledgeable when it comes to criminal law, and is an attorney that commands respect. I would highly recommend Jason to anyone."
Criminal defense Attorney | Aug 11
Relationship: Opposing Counsel on matter
"I have known Jason for several years both as a defense attorney and prosecutor. I have always found him to be highly professional, knowledgeable, and effective. I would highly recommend him."
Criminal defense Attorney | Aug 10
Relationship: Opposing Counsel on matter
"I endorse this lawyer. Jason was a prosecutor in Middlesex County and I had several cases against him over the years. I was extremely impressed with his knowledge, skill and dedication. I knew this would translate well as a defense attorney and offered him a job."
Criminal defense Attorney | Aug 09
Relationship: Opposing Counsel on matter
"I endorse this lawyer. Jason is a former prosecutor and we worked together on cases which he prosecuted and I defended. In light of my experiences with Jason I know that he is smart and tough and does a great job for his clients like he did for the State."
Criminal defense Attorney | Aug 08
Relationship: Worked together on matter
"I have known Jason Seidman for several years. He was a tough, knowledgeable, and extremely skilled prosecutor. He knows the law and every person in the Court system and Prosecutor’s office. He knows all the police and detectives. He is a extremely skilled trial attorney and an expert on criminal law. I highly endorse Jason Seidman."
Criminal defense Attorney | Aug 08
Relationship: Fellow lawyer in community
"I have known Jason for five years and worked on various matters with him during that time. He is knowledgeable, competent, and, when necessary, aggressive. I wholeheartedly endorse him as an attorney without hesitation or reservation."
Criminal defense Attorney | Aug 08
Relationship: Co-worker
"I endorse this lawyer. When I joined the firm, Mr. Seidman was welcoming in discussing our cases and potential arguments for our clients. Our discussions prove to me his experience and confidence in advocating vigorously on behalf of our clients."
Criminal defense Attorney | Jul 25
Relationship: Co-worker
"I have come across a multitude of attorneys in my time practicing the law. However, I would be hard-pressed to name a single one who is more intelligent, astute, and kind-hearted as Jason Seidman. He truly is a student-of-the-law. If Mr. Seidman is handling your matters, you can be assured that you are in competent and caring hands."
Criminal defense Attorney | Jun 27
Relationship: Co-worker
"I strongly endorse this attorney! This guy continues to impress me day in and day out with his hustle, dedication and knowledge of the law. Jay is the kind of guy who will never ask for a hand out - all of his accomplishments have been earned through shear determination and work ethic. He started his career as an intern at the Middlesex County Prosecutor's Office and soon gained the respect and recognition of the front office and he was hired as an Assistant Prosecutor. From there he quickly rose through the ranks to become the head of the drug task force. But what I find most impressive is how effectively he has transitioned into practicing criminal defense - something the vast majority of prosecutors are unable to do. Jay is one hell of a lawyer and an all around great guy and you would be lucky to have him represent you."
Criminal defense Attorney | Nov 10
Relationship: Opposing Counsel on matter
"I endorse this lawyer. Jason joined our firm six months ago after being a Middlesex County Prosecutor for five years. He has taken all his training and experience that he gained as a prosecutor and now uses it to vigorously advocate on his clients behalf."
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