Tampa Federal Criminal Defense Lawyer

Attorney Mark J. O'Brien

Mark J. O'Brien

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Practice Areas

  • Criminal Defense
  • Federal Criminal Defense
  • Federal Criminal Appeals and Post-Conviction Motions
  • State Criminal Defense
  • State Criminal Appeals and Post-Conviction Motions
  • White Collar Criminal Defense
  • Mortgage Fraud Criminal Defense
  • Securities Fraud Criminal Defense

Biography

PLEASE READ BEFORE CONTACTING US!!!

O'BRIEN HATFIELD, PA ONLY REPRESENTS INDIVIDUALS AND COMPANIES BEING INVESTIGATED, ACCUSED OR CHARGED WITH COMMITTING COUNTY, STATE OR FEDERAL CRIMES.

ATTORNEY MARK J. O'BRIEN AND HIS CRIMINAL DEFENSE TEAM AT O’BRIEN HATFIELD, PA ONLY REPRESENT INDIVIDUALS AND COMPANIES BEING INVESTIGATED, ACCUSED, OR CHARGED WITH COMMITTING COUNTY, STATE OR FEDERAL CRIMES.

  • THEY DO NOT FILE LAWSUITS. 
  • THEY DO NOT HANDLE CIVIL CASES. 
  • THEY DO NOT REPRESENT VICTIMS OF CRIME.
  • THEY DO NOT REPRESENT VICTIMS OF FRAUD.
  • THEY DO NOT SUE INDIVIDUALS OR COMPANIES.
  • THEY DO NOT REPRESENT VICTIMS OF BANK FRAUD.
  • THEY DO NOT SUE BANKS FOR STEALING OR LOSING CLIENT MONEY.
  • THEY DO NOT REPRESENT VICTIMS OF CREDIT CARD FRAUD.
  • IF YOU BELIEVE YOU ARE A VICTIM OF A CRIME, YOU WANT TO SUE SOMEONE, OR YOU NEED ASSISTANCE IN A CIVIL CASE, PLEASE CALL YOUR LOCAL BAR ASSOCIATION FOR AN ATTORNEY REFERRAL PROGRAM. PLEASE DO NOT CONTACT MR. O'BRIEN. HE REGRETS HE WILL NOT BE ABLE TO ACCEPT YOUR CASE. 


O'BRIEN HATFIELD, PA ONLY REPRESENTS INDIVIDUALS AND COMPANIES BEING INVESTIGATED, ACCUSED OR CHARGED WITH COMMITTING COUNTY, STATE OR FEDERAL CRIMES.

WHO IS FEDERAL ATTORNEY MARK J. O'BRIEN?

Mark J. O’Brien, Esquire is a nationally recognized Federal Criminal Defense Attorney with over 25 years’ experience in criminal courts all throughout the country. After beginning his professional career as a Miami, Florida prosecutor in the late 1990’s, Mr. O’Brien organized his own law firm in 2002 based upon the professional lessons he learned to that point in his life with the goal defending those accused of federal crimes with a mix of old school values and new school ideas.

During first decade in private practice from 2002 to 2012, Mr. O’Brien defended individuals and corporations charged with federal crimes throughout federal criminal courts in Florida. From 2012 to the present, Mr. O’Brien has accepted the defense of clients in federal criminal courts throughout the entire country, in addition to his previously established practice in all federal courts in Florida. Case after case, success after success, in federal court after federal court, all throughout the country, has resulted in a growing legacy. To put it simply, Mr. O’Brien wins and, as a result, he is a lawyer in demand.

Mr. O’Brien grew up in New York, attended law school near Philadelphia, Pennsylvania, and started his career in Miami, Florida. There is nothing he has not seen, done, or dealt with in and/or out of a criminal courtroom. New York raised, Philly tough, and Miami tested, Mr. O’Brien brings his 25 years of federal criminal court experience to those accused of federal crimes in federal criminal courts throughout the nation. Mr. O’Brien has the resources, both in his team and in his experience and his training, to tackle your federal criminal case and accomplish the only objective that matters: Win.

A FEDERAL CRIMINAL DEFENSE ATTORNEY WITH A FEDERAL CRIMINAL DEFENSE TEAM

In addition to his experience and training, Mr. O’Brien has built a full Federal Criminal Defense Team to assist him in defending his clients. Mr. O'Brien believes in hiring the best people to help him do his job. Similar to his role as a former prosecutor, Mr. O’Brien hired people who used to work in various federal law enforcement capacities. It is important to stay one step ahead of the other side. The only true way to accomplish this goal is to have done what the other side is going to do.

As a result, Mr. O'Brien supplements his experience and training with others who have very specific sets of skills. This includes a former Drug Enforcement Agency (DEA) Federal Special Agent, a former Internal Revenue Service (IRS) Criminal Investigation Division Federal Special Agent, a former United States Probation Officer, and a former law enforcement detective. Together, these four individuals have over 100 plus (over 25 years each) combined years’ experience in federal and state criminal courts throughout the country.

Once the above individuals are added to his 25 years of prosecutorial and federal criminal defense experience, Mr. O'Brien's team has well over a 125 combined years of federal and state criminal court experience to help you through this precarious time in your life.

FEDERAL CRIMINAL DEFENSE

The United States Constitution guarantees every individual the right to a fair trial and the presumption of innocence until proven guilty. This fundamental principle is upheld in federal criminal defense, where Mr. O’Brien works tirelessly to protect the rights of the accused.

The role of a federal criminal defense attorney is to provide legal representation to individuals charged with federal crimes. These crimes can range from drug trafficking and white-collar crimes to terrorism and espionage. The stakes are high, as a conviction can result in lengthy prison sentences, hefty fines, and a criminal record that can follow an individual for the rest of his or her life.

One of the key arguments in favor of hiring Mr. O’Brien for your federal criminal defense is the importance of protecting the rights of the accused. The Constitution guarantees the right to a fair trial, which includes the right to legal representation. Without a skilled attorney like Mr. O’Brien, a federal defendant may not fully understand their rights or the legal process, which can lead to an unfair trial and an unfair result.

Another argument in favor of hiring Mr. O’Brien is the need to ensure that the government follows due process. The government has vast resources at its disposal, including federal and state law enforcement agencies and prosecutors. A skilled defense attorney like Mr. O’Brien will level the playing field by challenging the government's evidence and ensuring that you are treated fairly.

White collar crime is a term used to describe non-violent crimes committed by individuals in positions of power or trust, typically in the business or financial sectors. These crimes can include fraud, embezzlement, insider trading, and money laundering, among others. When accused of such crimes, individuals often seek the white collar criminal defense services of Mr. O’Brien to represent them in federal criminal court.

Mr. O’Brien’s role is to protect the rights of his clients and ensure they receive a fair trial. This can involve challenging the evidence presented by the prosecution, negotiating plea deals, and presenting a strong defense case. In many cases, wherein trial is not the best option, Mr. O’Brien will work to mitigate the potential consequences of a conviction, such as fines, restitution, and most importantly imprisonment.

One of the key arguments in favor of retaining Mr. O’Brien is that everyone is entitled to a fair trial, regardless of the nature of the crime they are accused of committing. This is a fundamental principle of the American justice system, and it is the responsibility of the defense attorney to ensure that this principle is upheld. Additionally, Mr. O’Brien can help to prevent wrongful convictions by challenging the evidence presented by the prosecution and presenting a strong defense case with his federal criminal defense team.

Federal criminal defense attorney Mark J. O’Brien is a crucial component of the American justice system. He ensures that the rights of the accused are protected, and that the government follows due process. While the stakes are high, a skilled federal criminal defense attorney like Mr. O’Brien can make a significant difference in the outcome of a federal case.

Why play games with your life?

How long have you been an attorney?

Although it seems like just yesterday that I started my legal career, I have been an attorney for over 25 years. They say that time flies when you love what you do and I certainly love what I do. Having been both a Miami prosecutor and a large firm defense practitioner, I made the decision nearly two decades ago to combine my different legal experiences to form a countrywide federal and statewide state criminal defense law firm. Over the course of my two decades as an attorney, I have handled many of the most complex state and federal criminal cases in the State of Florida, and in federal courts all over the country. I understand and appreciate what is at stake when someone hires me. It consumes me and becomes my life.

What state bar exams have you passed?

Three. I am a member of the Bars of the the State of Florida, the State of Montana, and the Commonwealth of Massachusetts. The summer after I graduated law school I simultaneously, and on my first attempt, passed the Bar Exams of the Commonwealth of Massachusetts and the State of Florida. Those two bar exams amounted to three straight eight hour days of testing in two different states. I finished the Florida Bar Exam at 5:00 pm and flew that same night to Boston, Massachusetts to take the Massachusetts Bar Exam the next morning. So when I say took and passed the Massachusetts and Florida Bar Exams simultaneously, I literally mean that I took and passed them simultaneously - with the help of an airplane of course. In 2023, I became a member of the Bar of the State of Montana.  

Bar Admissions

  • State of Florida, 1998
  • Commonwealth of Massachusetts, 1998
  • State of Montana, 2023
  • Supreme Court of the State of Florida
  • Massachusetts Supreme Judicial Court
  • Montana Supreme Court
  • Supreme Court of the United States
  • U.S. Court of Appeals 1st Circuit
  • U.S. Court of Appeals 2nd Circuit
  • U.S. Court of Appeals 9th Circuit
  • U.S. Court of Appeals 11th Circuit
  • U.S. District Court Northern District of Alabama
  • U.S. District Court Eastern District of Arkansas
  • U.S. District Court Central District of California
  • U.S. District Court District of Connecticut
  • U.S. District Court Southern District of Florida
  • U.S. District Court Middle District of Florida
  • U.S. District Court Northern District of Florida
  • U.S. District Court Southern District of Georgia
  • U.S. District Court Middle District of Georgia
  • U.S. District Court Northern District of Georgia
  • U.S. District Court Southern District of Illinois
  • U.S. District Court Southern District of Indiana
  • U.S. District Court Eastern District of Kentucky
  • U.S. District Court District of Massachusetts
  • U.S. District Court Western District of Michigan
  • U.S. District Court Southern District of Mississippi
  • U.S. District Court Western District of Missouri
  • U.S. District Court District of Montana
  • U.S. District Court Southern District of New York
  • U.S. District Court District of North Dakota
  • U.S. District Court Northern District of Oklahoma
  • U.S. District Court District of Rhode Island
  • U.S. District Court Eastern District of Texas
  • U.S. District Court Western District of Texas
  • U.S. District Court Northern District of Texas
  • U.S. District Court for the Eastern District of Virginia
  • U.S. District Court Eastern District of Washington
  • U.S. District Court Western District of Washington
  • U.S. District Court Southern District of West Virginia

Professional Associations

  • American Association for Justice, Member
  • National Association of Criminal Defense Lawyers, Member
  • Florida Association of Criminal Defense Lawyers, Member
  • Florida Bar Association, Member
  • Federal Bar Association, Member

Published Works

  • "Strategies For Defending Identity Theft Cases", Aspatore, 2012

Representative Cases

  • Hulk Hogan v. Gawker Media, LLC (represented non-party witness Bubba the Love Sponge)
  • Florida Bar v. Adam Filthaut (prominent trial attorney accused of DUI setup in Bubba/MJ trial)
  • United States v. Jeanette Hevel (former Tampa Police Department Captain)
  • United States v. John Wilson (former Washington Redskin NFL player)
  • United States v. Rashia Wilson (IRS fraud)
  • United States v. Robert Blango (notorious Fort Myers bank robber)
  • United States v. Senad Djedovik (infamous Norwegian Cruse Lines employee)
  • State of Florida v. Rougned Odor (current Texas Ranger MLB player)
  • State of Florida v. Jerramy Stevens 1 (former Tampa Bay Buccaneer NFL player)
  • State of Florida v. Jerramy Stevens 2 (former Tampa Bay Buccaneer NFL player)
  • State of Florida v. Jerramy Stevens 3 (former Tampa Bay Buccaneer NFL player)
  • State of Florida v. Matthew Buendia (former United States Marine charged with shooting a police officer)
  • State of Florida v. Mary Lynn Vu (teacher accused of having sex with her student)

Classes & Seminars

  • Lecturer, Trial Advocacy Skills, Intensive Trial Advocacy Program (ITAP)

Past Positions

  • Office of the Miami-Dade County State Attorney

Languages

  • English
  • Spanish