“They weren’t using live ammunition,” he said. “They would painstakingly make sure everything was unloaded and simulate live ammunition.”
Police would not offer any details about Tuesday’s training exercise, saying that information was part of their investigation. In recent years, police have described using “active shooter” training exercises in which officers use so-called “simunition” bullets similar to paintballs.
Simunitions are fired from a standard handgun and explode on impact. They allow officers to practice in realistic situations, often in abandoned buildings.
The former Rosewood Center dates to 1888 and once housed as many as 3,000 patients with developmental disabilities. Its population dwindled to 166 residents by 2010, when Gov. Martin O’Malley ordered its closure. Most of the remaining residents were relocated to group homes.
State troopers, Baltimore County police and Baltimore police milled in a parking lot in front of a low brick building on the campus Tuesday afternoon.
Sonya Boyce, a private security guard who watches over the abandoned buildings, said police told her only that there had been an accident. Boyce said that a number of agencies train at the facility but that she had never seen city officers there until recently.
In the early afternoon, Baltimore County police cruisers blocked the cracked concrete roads that link the eerie abandoned buildings that once housed patients. Later, the county police left and were replaced by state troopers. Shortly before dusk, a Baltimore police minibus left with trainees wearing uniforms of a tan shirt and dark pants.
The property, which includes 178 acres and more than 30 buildings constructed in the late-19th century through the 1960s, has been up for sale. Stevenson University had expressed interest in purchasing the land.
However, concerns have been raised over costs to remove hazardous materials, including lead, asbestos and PCBs, toxic chemicals from coal ash dumping and leaking oil tanks.
Although no local agencies have reported police trainees being injured during training exercises in recent years, a Baltimore fire recruit died during a live burn exercise in 2007 at an abandoned rowhouse.
Racheal M. Wilson’s death halted live-burn exercises in the city, and Howard and Montgomery counties temporarily banned the training exercises. Wilson’s death also resulted in a top fire official losing his job.
Investigations into the training found the house was unsafe and that more than 30 national safety standards were not followed during the planned blaze.
Baltimore Sun reporter Ian Duncan contributed to this article.