Baltimore prosecutors announced the arrest of 24-year-old Dion Thompson in connection with the cold case homicide of off-duty Washington, D.C., police officer, Sgt. Tony Anthony Mason Jr., who was shot to death in 2017 while sitting in a parked car with a woman he had been dating. The case remained unsolved for five years until detectives received a tip in 2023 that led to charges against Thompson, who was 18 at the time of the shooting and is currently serving time in a federal prison on unrelated charges. Thompson is accused of shooting up the parked car because he thought the occupants were there to rob or retaliate against him for past crimes, and later learned from the news that Mason was a police officer, prompting him to dispose of the vehicle involved in the shooting in Philadelphia.
Investigators revealed that Thompson was the leader of a gang called “The Slickest Ones” or TSO, and he allegedly worked with accomplices known as “Man-man” and “Chub” in carrying out the shooting. One of the accomplices died in a car crash, and no one else has been charged in connection with the case. Mason, a 17-year veteran of the Metropolitan Police Department, was unarmed during the attack and had no identifying clothing as a law enforcement officer. Background checks on Mason and his companion revealed no criminal or gang activity. Chief Pamela Smith of the Metropolitan Police Department expressed relief that the responsible person is being brought to justice after years of painful mystery surrounding Mason’s death.
Thompson’s charging documents do not provide a clear motive for the shooting and rely heavily on the account of a witness who knew him but did not witness the crime. The witness stated that Thompson admitted to shooting the car out of paranoia, assuming that the occupants were there to harm him. Thompson’s attorney in an unrelated matter clarified that he is not representing him in the murder case, which is not yet listed in online records. Baltimore State’s Attorney Ivan Bates announced that this will be the first prosecution handled by his office’s new cold case unit, signaling a commitment to resolving unsolved cases and bringing closure to families of victims. Mason’s death had prompted a $20,000 reward for information leading to the arrest of his killer, which contributed to the renewed investigation that led to Thompson’s arrest.
The case of Sgt. Tony Anthony Mason Jr.’s murder underscored the risks faced by law enforcement officers even when they are off duty, as Mason was shot while sitting in a parked car with a companion. The crime remained unsolved until a tip reignited the investigation and led to Thompson’s arrest several years later. Thompson’s alleged involvement in the shooting, as the leader of a gang, and his actions after the incident were detailed in charging documents that linked him to the crime. His prosecution will provide a sense of justice for Mason’s family and colleagues, who have been waiting for closure and answers for years. The collaboration between jurisdictions in solving the case demonstrates the dedication of law enforcement to pursuing justice and holding those responsible for violent crimes accountable.
While the details of Thompson’s motive and the specifics of the crime remain unclear, the witness’s account provided the necessary evidence to bring charges against him. Thompson’s actions following the shooting, including disposing of the vehicle and potentially collaborating with accomplices, further implicated him in the crime. The announcement of his arrest and impending prosecution marked a significant development in the case, which had remained unsolved for an extended period. With Thompson’s arrest, law enforcement officials hope to bring closure to Mason’s family and colleagues, who have been mourning his death and seeking justice for years. The case serves as a reminder of the dangers faced by law enforcement officers both on and off duty, and the importance of resolving cold cases to ensure that perpetrators are held accountable for their actions.
