Man convicted in 2017 cold case murder of off-duty D.C. police officer in Baltimore
A man was convicted nearly nine years after an off-duty Washington, D.C. police officer was shot to death while sitting in a parked car in Baltimore.
Dion Thompson was found guilty of first-degree murder, conspiracy, and related charges for the 2017 murder of D.C. Metro Police Sgt. Tony Mason. He was also convicted of attempted second-degree murder for a non-fatal shooting of a woman who was with Mason.
Thompson will be sentenced on August 5, when he faces two life sentences plus 33 years in prison.
"The loss of Sgt. Mason is still fresh in the hearts of his family and his brothers and sisters on the DC Metro Police force," Baltimore City State's Attorney Ivan Bates said. "I sincerely appreciate all the tireless work by Chief Kurt Bjorklund, BPD, the FBI, and ATF to pursue this prosecution relentlessly. Their perseverance has delivered justice for the Mason family. As the inaugural case that launched our office's Cold Case Homicide Unit, this prosecution holds a special place in our hearts as ministers of justice."
Solving the cold case murder
In November 2017, 40-year-old Sgt. Mason was shot and killed while sitting in a parked car on Elgin Avenue with a woman he had been dating, according to police. The woman was also shot but survived.
The case went unresolved for nearly six years before detectives received a tip in 2023, which sparked the investigation and led to murder charges against Thompson, who was 18 years old at the time of the homicide.
At the time of Thompson's arrest in 2024, Thompson was serving time in a federal prison on unrelated drug and gun charges.
The D.C. Metro police said Mason was a 17-year veteran of the department.
"For nearly a decade, Sgt. Mason's death has weighed heavily on his family, our Department, and the community he served. Throughout this long journey, our partners at the Baltimore Police Department, the FBI, the ATF, and the Baltimore City State's Attorney's Office never stopped pursuing answers. Their commitment brought us to this moment," said D.C. Metro Interim Chief of Police Jeffery Carroll. "We hope this verdict provides some measure of peace for everyone who continues to feel the weight of his loss."
Victim was a case of mistaken identity
According to charging documents obtained by CBS News Baltimore, Sgt. Mason was unarmed and wasn't wearing any clothing that revealed himself to be a police officer.
Charging documents revealed that a person told officers that Thompson admitted to shooting at the parked car because he became paranoid, thinking they "were there to either rob him or retaliate against him for all the robberies he was committing."
Thompson reportedly found out the victim was an off-duty officer after watching the news. Prosecutors in the case said Thompson drove to Philadelphia to get rid of the vehicle he was driving the night of the shooting.
Investigators said that Thompson was the leader of a gang called "The Slickest Ones" or TSO, according to court documents.
Police said Thompson teamed up with accomplices going by the street names of "Man-man" and "Chub" to carry out the shooting. One of them later died in a car crash.
"Our detectives never stop working to seek justice for victims and their families," Baltimore Police Commissioner Richard Worley said. "This conviction is the result of hard work and collaboration with our partners at the State's Attorney's Office, FBI, and ATF. Most importantly, this conviction brings justice to Sgt. Mason's family and honors his memory and service."
