Mark J. O'Brien

O'Brien Hatfield, PA is a criminal defense law firm that focuses on nationwide federal criminal defense and statewide criminal defense and criminal appeals. Attorney Mark J. O'Brien is the firm's founder and managing partner. He handles federal criminal cases in federal criminal courts statewide and in federal criminal courts throughout the United States. Formerly a Miami prosecutor, Mark is now widely lauded by federal judges and federal prosecutors as one of the best federal defense attorneys in the country. Mark is so in demand that his office is often an airplane with a WiFi connection. Despite reaching such great heights, Mark still treats each case with the same enthusiasm and energy as he did his first (even though he has practiced law for over twenty-five years).

O’Brien Hatfield, PA has a support staff of paralegals, legal assistants, and private investigators. They have multiple office locations throughout the state and the country. They have the resources necessary to leave no stone unturned - and an unmatched desire to win.

WHO IS 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?

Mr. O’Brien handles all federal criminal court areas of practice, including but not limited to: Federal White Collar Criminal Defense, Federal Sex Crimes Defense, Drug Crimes, Gun Crimes, Conspiracy Crimes, General Federal Criminal Defense, Federal Grand Jury Investigations and Pre-File Criminal Investigations.

Mr. O’Brien has been a member of the Bar of the State of Florida and the Bar of the Commonwealth of Massachusetts since 1998. He has been a member of the Bar of the State of Montana since 2023. In addition, he is a member of the Supreme Court of the United States, the Supreme Court of the State of Florida, the Massachusetts Supreme Judicial Court, the Montana Supreme Court, and he has appeared as a member or a pro hac vice member before many federal district courts.

If you are being investigated and/or prosecuted by federal agents and/or federal prosecutors and are need of a Federal Criminal Defense Attorney – and a Federal Criminal Defense Team – anywhere in the United States of America, all Mr. O’Brien needs is a Wi-Fi Password and a plane to defend you.