Press Releases

Baltimore (Md.) April 17, 2024 - Today, State's Attorney Ivan J. Bates joined FBI Baltimore, ATF Baltimore, the Baltimore Police Department, the Maryland Crime Victims' Resource Center and the DC Metropolitan Police Department to announce charges against Dion Thompson for the murder of DC Metropolitan Police Sgt. Tony Mason, Jr., which will be the first case prosecuted by the State's Attorney's Office newly created Cold Case Unit.

"A cold case is still very much fresh in the hearts and minds of the victim's family. My main job as State’s Attorney is holding offenders accountable, bringing closure for those impacted, and ensuring justice for Baltimore, the victims, and their loved ones," said State's Attorney Ivan J. Bates. “It is critically important that we utilize the latest investigative techniques and technology to put fresh eyes on once-forgotten crimes in an effort to bring closure to those who were impacted while sending the message to offenders that their malicious acts will not go unaddressed. I sincerely appreciate all the tireless work by Senior ASA Kurt Bjorklund, BPD, the FBI, and ATF, and I am especially thankful for the continued support of the Metropolitan Police Department." 

Thompson has been charged with First-Degree Murder, Conspiracy, and related charges for allegedly shooting Sgt. Mason while he was off-duty in November of 2017 at the 2800 block of Elgin Avenue.

This is not a finding of guilt. An individual charged is presumed innocent unless and until proven guilty at trial.

"For far too long, the details surrounding Sergeant Mason's tragic death have remained a painful mystery. However, the Baltimore Police Department, the FBI, the ATF, and the Baltimore City State’s Attorney’s office never stopped following up on tips and tracking down leads," said Metropolitan Police Department Chief Pamela A. Smith. "This arrest is a testament to the dedication of our law enforcement community and the collaborative efforts between agencies. While we cannot erase the pain of loss or the memories of that day, we can take solace in the fact that the person responsible is being brought to justice."

Cold cases are generally defined as those unsolved criminal investigations that remain open pending the discovery of new evidence. These cases were not solved initially through traditional means; “fresh eyes” are often needed to review existing work and pursue different avenues. The goal of the cold case investigator is not always to solve the case but to push forward the investigation meaningfully; often, these incremental steps lead to more significant advancements.

“By partnering with the State’s Attorney’s Office Cold Case Unit, we can work toward the shared goal of moving cases forward and bringing closure to victims’ families. This should also put the perpetrators of these crimes on notice: You will get caught, and you will be held to account,” said Baltimore Police Commissioner Richard Worley. “I specifically would like to emphasize the BPD’s Cold Case Squad’s tireless efforts in tracking down the suspect in the homicide case of Sgt. Tony Mason, Jr. I am also grateful to the State’s Attorney’s Office, the FBI, ATF, and the DC Metropolitan Police Department. I hope this brings his loved ones some peace, and I look forward to this partnership leading to the resolution of many more cases.”

The Cold Case Unit will work co-extensively with the existing Baltimore Police Department Cold Case Unit to ensure that these unique cases are investigated with better coordination and specialization. The case against Mr. Thompson will be led by the Unit’s new director, Senior Assistant State’s Attorney Kurt Bjorklund, a prosecutor with almost twenty years of service, including both extensive homicide prosecution and management experience. Last year, ASA Bjorklund successfully prosecuted State of Maryland v. Michael Robertson, a cold case, “no body” homicide, where the defendant received two consecutive life sentences for the May 2017 murder of Akia Eggleston and her unborn child.

"I’m honored that State’s Attorney Bates entrusted me with beginning this important project for our office. My entire career has been devoted to achieving justice for victims of violent crimes and their families and holding violent offenders accountable. Focusing on older homicide investigations will allow me to continue that pursuit while employing the newest evidentiary tools and creative strategies,” Senior Assistant State’s Attorney Kurt Bjorklund said.

The Robertson case served as proof of concept, supporting the theory that cold case homicides should be specifically assigned to those prosecutors with the necessary experience, skill set, and availability of resources. Currently, cold case homicides are assigned along with fresh investigations among the attorneys of the Homicide Unit. The attorneys tasked with prosecuting homicide in Baltimore City are the absolute best in the country. Still, due to enormous caseloads, their availability is limited to take on cold case homicides, which tend to require more attention per case.

The State's Attorney's Office plans to expand the unit gradually, contingent upon obtaining available Federal funding allocated primarily for DNA testing and Forensic Genetic Genealogy investigations. In addition, the City will unfreeze several job position "pins" assigned to the agency to build up the staffing needed to keep up with the work and resources these types of investigations require.

"While nothing will bring Sergeant Mason back or end his family’s pain, we hope they can take some comfort in knowing that law enforcement will not stop pursuing justice and holding accountable anyone found responsible for taking the life of one of our own,” said William J. DelBagno, Special Agent in Charge of the FBI Baltimore Field Office. “The FBI, along with our local, state and federal partners, remains committed to removing violent offenders from our streets to ensure a safer environment for all Maryland residents.”

The charges against Mr. Thompson resulted from a thorough inter-agency investigation conducted by the Baltimore Police Department Homicide Section, the Federal Bureau of Investigation, and the Bureau of Alcohol, Firearms, and Tobacco. This is yet another example of an older case that benefitted from focused attention and resources.

“ATF prides itself on strong partnerships among our law enforcement and prosecutorial partners, and this is an excellent illustration of how working alongside the FBI, Baltimore Police Department and State’s Attorney’s Office, is a force multiplier when it comes to investigating and prosecuting violent crimes in our community,” commented ATF Baltimore Special Agent in Charge Toni M. Crosby. “I commend the State’s Attorney’s Office for their commitment in prosecuting these important cases.”

Anyone with additional information into the murder of DC Metro Police Sgt. Tony Mason, Jr. should contact the Baltimore Police Department Homicide Unit at 410-396-2100 or Metro Crime Stoppers at 1-866-7LOCKUP.

Charging documents for Dion Thompson can be found here. Victim and witness identifying information has been redacted.