Jennifer Holly O'Brien

Jennifer Holly O'Brien

5.0
Rating: 10.0

Licensed for 29 years

Criminal defense Lawyer at Billerica, MA
Practice Areas: Criminal Defense, Appeals, Personal Injury

630 Boston Road, Billerica, MA

About Jennifer

Biography

Practice Areas

3

Practice Areas

Criminal Defense 50%

Providing criminal defense in the District, Superior and Federal Courts for both misdemeanor offenses and serious felonies including first degree murder. Bar advocate for Middlesex Defense Attorneys.

30 years

50%
Appeals 40%

Has handled hundreds of appeals in the Appeals Court, Supreme Judicial Court, and Court of Appeals for the Federal Circuit. Bar advocate at the appellate level for all criminal cases from misdemeanor convictions to first degree murder convictions.

30 years

40%
Personal Injury 10%

Has over 25 years experience representing plaintiffs in wrongful death cases, or otherwise injured in car accidents, slip and fall accidents, and dog bites.

30 years

10%

Fees and Rates

We have not found any cost information for this lawyer


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Licenses

Licensed in Massachusetts for 29 years

State: Massachusetts

Acquired: 1996

Active

No misconduct found

Location

Law Offices of Jennifer Holly O'Brien

630 Boston Road, Billerica, MA, 01821

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Jennifer Holly O'Brien's Reviews

Avvo Review Score

5.0 /5.0

21 Client Reviews

Filter Avvo Reviews (21) Refine reviews to match your needs. Use the filters to quickly surface reviews that align with your case or priorities.

Showing 1 - 5 of 7 reviews | Practice Area Knowledge

Posted by anonymous | February 10, 2026 | Hired Attorney | Criminal Defense

Knowledgeable, Strategic, and Trustworthy Criminal Defense Attorney

Attorney Jennifer O’Brien is highly knowledgeable in criminal defense. This was our first time facing a legal situation, and what began as an exaggerated matter was handled with professionalism and care. She guided us through the process clearly and confidently, and her strategy and coordination with... the District Attorney’s office led to a dismissal of the case. We truly appreciate her expertise, responsiveness, and reassurance throughout the process. I would absolutely recommend Jennifer O’Brien to anyone seeking peace of mind and the best possible outcome, and I would not hesitate to hire her again.

Posted by Tyrell | September 18, 2016 | Hired Attorney | Criminal Defense

The Best Lawyer Ever!

I hired Jennifer for a criminal case that I had. The cops pulled me over in Lowell and searched my car. I was charged with drug possession. I met with Jennifer and she read my police report. Immediately she said that this was an illegal search and that there is a good chance that we can get this case... dismissed. We had a hearing where she made the cop look like a fool. We won the hearing and because of it the prosecution dropped the case. I hope I never get arrested again, but if I do I will be hiring Jennifer. She is the best attorney I have ever had!

Posted by Jill | September 15, 2016 | Hired Attorney | Wills & Living Wills

Great lawyer, recommend to family & friends

Anytime I or someone I know needs a lawyer Jen is the first one I think of & recommend. She did a wonderful job with our wills & health proxies giving us a little piece of mind. Jen also helped a family member with a divorce. She fought for her clients best interest & made a difficult situatio...n very manageable.

Posted by J. Lisa | September 13, 2016 | Hired Attorney | Family

Highly Recommended!!

Attorney O'Brien is someone you would want on your side. Her years of experience reflect in her professional disposition as in my case. Attending court is never easy and can be very stressful, however Attorney O'Brien is someone who you can trust and will represent your best interests to the fullest.... She represented my case in a family dispute. I highly recommend Attorney O'Brien.

Posted by D. Miller | August 31, 2016 | Hired Attorney | Appeals

Amazing Appellate Attorney

Jennifer was my appellate lawyer for a Murder 1 appeal, she did an amazing job, she was attentive, answered all & any of my questions in full detail, explained each element of my case, case errors & correspondence in full detail, she guided me through a very tough time of life to the best ability. Je...nnifer also researched & argued my case & case errors to the fullest, she kept me very updated & informed on all court proceedings, she is always available to take my calls. Jennifer put her heart & soul into not just my appeal, but also fighting for my rights & my family & for that I can not thank her or her staff enough.

See All Client Reviews

Jennifer Holly O'Brien's Lawyer Endorsements

Endorse Jennifer
Lorenzo Perez headshot
Lorenzo Perez

Criminal defense lawyer | Jan 16

Relationship: Worked together on matter

"Attorney O’Brien is at the top of the profession! She’s an extraordinarily talented and successful attorney. Her intelligence, diligence, and tenacity make her the lawyer any client would be blessed to have in their corner. I rely on her counsel often to cooperatively defend clients who find themselves in the most challenging of circumstances. Whether the legal matter is an appeal, or a complex trial with formidable challenges -- without a doubt -- Attorney O’Brien is the lawyer I want on my side; and, clients with everything at stake would be extremely fortunate to have her on their side. She’s a no-nonsense, highly experienced, imminently experienced attorney!"

Frank Dennis Camera headshot
Frank Camera

Appeals lawyer | Apr 02

Relationship: Worked together on matter

"Attorney O'Brien is a brilliant appellate advocate and trial attorney. I have worked with her on many matters and she truly is a creative, diligent and passionate attorney. I would recommend Attorney O'Brien to any attorney seeking professional guidance or creative solutions to complex legal matters."

Gregory D. Oberhauser headshot
Gregory Oberhauser

Divorce and separation lawyer | Sep 17

Relationship: Fellow lawyer in community

"I endorse this lawyer. Jen is that type of lawyer who gets it! She understands the issues of divorce and all of her cases and clients. She knows what needs to be done. She is realistic about what goals are acceptable and what are not. She is up front with the client, especially those i have sent to her, they all have been very happy with the service and results she has accomplished. Jen has that way of telling you what is real and not real -- my clients need to hear this and they appreciate the advice. I have known Jen for over 15 years as a lawyer and friend, have appreciated the mutual support we have grown to expect."

Jeffrey A. Higgins headshot
Jeffrey Higgins

DUI and DWI lawyer | Sep 15

Relationship: Fellow lawyer in community

"I endorse this lawyer."

James P. Haroutunian headshot
James Haroutunian

Divorce and separation lawyer | Sep 06

Relationship: Fellow lawyer in community

"Attorney O'Brien is a rare lawyer who provides exceptional service at a reasonable rate. Her office is run with efficiency and personal care. All clients (which I have gladly referred over the past decade) have expressed joy with her service."

Daniel E Dalton headshot
Daniel Dalton

Family lawyer | Sep 05

Relationship: Opposing Counsel on matter

"I endorse this lawyer."

John P. Miller headshot
John Miller

Criminal defense lawyer | Aug 30

Relationship: Co-worker

"I have worked with Jennifer for many years and I can say unequivocally that she is an outstanding criminal defense and appellate lawyer. She is very knowledgeable about the law, and her tremendous writing ability and keen eye for issue spotting allow her to advocate for her client's in a way that only an attorney with 20 years of experience can. I cannot recommend Jennifer highly enough; not only is she a tremendous attorney, but her thorough preparation of every case allows her clients to breathe easier knowing they are in very capable hands."

William Scott Smith headshot
William Smith

Criminal defense lawyer | Jan 15

Relationship: Worked together on matter

"Jennifer is an exceptionally skilled criminal defense lawyer in my opinion. I have worked with her on major felony cases, including murder appeals. Most importantly, she is down to earth, cares deeply about her clients’ cases, and fights for her clients tirelessly. I highly recommend her!"

Keren E Goldenberg headshot
Keren Goldenberg

Criminal defense lawyer | Dec 21

Relationship: Fellow lawyer in community

"Jennifer is a great trial and appellate lawyer. I highly recommend her."

View All Endorsements
Lorenzo Perez headshot
Lorenzo Perez

Criminal defense lawyer

David Hayes Erickson headshot
David Erickson

Personal injury lawyer

Jeffrey A. Higgins headshot
Jeffrey Higgins

Criminal defense lawyer

James P. Haroutunian headshot
James Haroutunian

Estate planning lawyer

Daniel E Dalton headshot
Daniel Dalton

Divorce and separation lawyer

Gregory D. Oberhauser headshot
Gregory Oberhauser

Bankruptcy and debt lawyer

William Scott Smith headshot
William Smith

Appeals lawyer

John P. Miller headshot
John Miller

Divorce and separation lawyer

Frank Dennis Camera headshot
Frank Camera

Criminal defense lawyer

Keren E Goldenberg headshot
Keren Goldenberg

Criminal defense lawyer

Experience

Rating:  10.0 (Superb)

Honors

2025

Super Lawyer, Super Lawyers Magazine

2024

Super Lawyer, Super Lawyers Magazine

2023

Voted superlawyer for criminal defense, Super Lawyers Magazine

2022

Voted Super Lawyer for criminal defense, Super Lawyer’s magazine

2021

Voted Superlawyer for Criminal Defense, SuperLawyers Magazine

2020

Voted Superlawyer for Appellate Practice, Superlawyers Magazine

2017

Favorite Billerica Attorney - 1st place, Wicked Local Magazine Reader's Choice

2017

Favorite Regional Attorney - 2nd place, Wicked Local Reader's Choice

2016

Favorite Attorney-Honorable Mention, Wicked Local Reader's Choice

Work Experience

1998 - Present

owner, O'Brien Law Offices

Associations

1996 - Present

Middlesex County Bar Association

1996 - Present

Greater Lowell Bar Association

Sample of Legal Cases

Commonwealth v. Bennett

Me trial awarded, and case dismissed after defendant serves 19 years.

Commonwealth v. Rufo

Convictions vacated

Commonwealth v. Oliver

Motion to suppress allowed and case dismissed

Commonwealth v. Sien

motion to suppress allowed - case dismissed

Commonwealth v. Raba

conviction reversed and vacated

Commonwealth v. Morris

conviction reversed and vacated

Commonealth v. Queenan

conviction reversed and vacated

Commonwealth v. Enwonwu

conviction reversed and vacated

Commonwealth v. Santana

conviction reversed and vacated

Commonwealth v. Hill

guilty plea vacated and new trial awarded

Commonwealth v. Hallisey

conviction reversed and vacated

Commonwealth v. Hunt

new trial motion allowed

Commonwealth v. Fidalgo

conviction vacated and new trial awarded

Commonealth v. Vlahos

new trial motion allowed

Commonwealth v. Tabi

new trial motion allowed

Commonwealth v. Ramirez

conviction reversed and vacated

Commonwealth v. Alger

conviction reversed and vacated

Commonwealth v. Ruehle

conviction vacated and new trial awarded

Commonwealth v. Darnell D.

conviction reversed and vacated

Commonwealth v. Scrima

conviction vacated and new trial awarded

Commonwealth v. Kivlehan

conviction reversed and vacated

Commonwealth v. Bogale

new trial motion allowed

Commonwealth v. Ameral

conviction reversed and vacated

See More Legal Cases

Education

1996

New England School of Law

JD - Juris Doctor

1992

University of Massachusetts, Amherst

BA - Bachelor of Arts

Speaking Engagements

2010

Greater Lowell Bar Association CLE

Appellate Advocacy

Publications

2011

Billerica Green Newspaper Properly Insured Keeps Drivers Safe

2011

Billerica Green Newspaper Laid-Off and Child Support

2010

Billerica Green Newspaper Simple Homestead Protection

2010

Billerica Green Newspaper Small Claims Court

2010

Billerica Green Newspaper Physical vs. Legal Custody

2010

Billerica Green Newspaper Divorce Settlement Equation

2010

Billerica Green Newspaper Obtaining a Will, Made Easy

Languages

English

Activity

Avvo Rating

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