Security guard pleads guilty in Northrop Grumman killing in Anne Arundel County

A former security guard at a Northrop Grumman facility in Anne Arundel County has pleaded guilty to second-degree murder in the shooting death of his supervisor in January 2026.

The plea was entered by 27-year-old Dylan Blake Chandler Thursday in Anne Arundel County Circuit Court, said a statement issued by the State's Attorney's Office. Chandler is from Pasadena, Maryland. 

Chandler also pleaded guilty to a count involving use of a firearm in a crime of violence in connection with the killing of 37-year-old Joseph Keith Aman of Baltimore.     

Judge Cathleen Vitale set sentencing for Chandler on Dec. 15, 2026.

"Investigators believe the defendant did not premeditate or plan to commit murder, but rather killed the victim following being reprimanded for workplace conduct," said Anne Arundel County State's Attorney Anne Colt Leitess. "This is a horrible tragedy. My heart goes out to the family of Mr. Aman, who have suffered a devastating loss due to this defendant's irrational actions."

Officers responded around 3:30 p.m. Wednesday to the facility in Linthicum, in Anne Arundel County. 

Police said the shooting happened in an office during a meeting between Aman and Chandler to discuss Chandler's performance. According to court documents, the performance issues were "likely to result in Mr. Chandler being reprimanded or terminated."

Police said a third security worker who was in the room intervened, took away Chandler's gun, and kept him restrained. The Maryland Transportation Authority Police responded, followed by the Anne Arundel County Police.

Police said there were other employees inside the building at the time of the shooting.