A 25-year-old Southeast Baltimore man has been charged with fatally injuring an off-duty Baltimore police detective by throwing a piece of concrete at the officer's head during an argument over a Canton parking space, according to police.

Detective Brian Stevenson, an 18-year veteran and married father of three, had gone out to have dinner on the eve of his birthday when he and Sian James got into an altercation in a private parking lot in the 2800 block of Hudson St. about 10 p.m. Saturday, police said. James was charged Sunday with first-degree murder.

James struck Stevenson in the left temple with a "fist-sized" concrete fragment, according to court records. Stevenson suffered "massive head injuries" and was taken to Johns Hopkins Bayview Medical Center, where he died about an hour before he was to have turned 38.