Before Baltimore City Circuit Court Judge Cynthia H. Jones, a federal inmate testified July 28 that Dion Thompson, 27, confessed to fatally shooting off-duty Metropolitan Police Department Sgt. Anthony “Tony” Mason Jr., 40, while the two were incarcerated together, telling him Mason’s “ghost” later appeared and strangled him.
Thompson is charged with first-degree murder, attempted first-degree murder, conspiracy to commit first-degree murder and multiple firearm offenses in connection with the Nov. 4, 2017 shooting that killed Mason and wounded his girlfriend.
The retrial follows a March 2025 jury trial that ended in a mistrial after jurors were unable to reach a unanimous verdict.
The state’s first witness, a federal inmate, testified that he met Thompson while both were incarcerated at Fort Dix before later becoming cellmates in the Special Housing Unit.
The witness testified that during a conversation about ghosts, he told Thompson he believed his deceased mother had appeared to him. According to the witness, Thompson responded that the man he had killed also appeared to him as a ghost and was “strangling” him.
In additional testimony the witness claimed Thompson later admitted he shot Mason because he believed the victim would retaliate against him over “street stuff.”
According to the witness, Thompson told him he pulled alongside Mason’s vehicle and opened fire and stated to his cellmate, “You should’ve seen his face.”
The witness also testified Thompson said he went to his brother’s house looking for more bullets after the shooting, but his brother refused because he would never kill anyone.
According to the witness, Thompson then told his brother, “Watch the news. I got one today, dummy.”
The witness testified he ultimately contacted law enforcement because his own mother had died from gun violence and he did not want another homicide weighing on his conscience. During direct examination, he denied receiving or expecting any reward money, sentence reduction or other benefit in exchange for his testimony.
During cross-examination, defense attorney Staci Pipkin questioned the witness about his federal sentence, prison transfers and whether he hoped to receive favorable treatment for cooperating with investigators. He denied receiving any benefit.
The state’s second witness testified she knew Thompson from middle school and that one of her brothers was friends with him.
Throughout her testimony, prosecutors repeatedly asked the witness to answer questions verbally rather than with gestures. The prosecutor noticed the witness’s demeanor and asked “Is there a reason you’re having attitude today?”
The witness replied, “I don’t have an attitude.”
Judge Jones briefly called counsel to the bench before testimony resumed.
The state’s final witness was the lead Baltimore Police Department (BPD) homicide detective assigned to the investigation.
The detective, a 28-year veteran of the force
identified the crime scene photographs, the evidence collected during the investigation, and the autopsy photographs shown to jurors.
The trial is scheduled to continue July 29.
