A city employee was killed outside Baltimore City Hall after a vehicle sped off an interstate and onto downtown streets, flipping the car he was driving as he tried to make a turn. (Christopher T. Assaf/Baltimore Sun video)

Shipley said troopers consider a long list of factors before initiating a pursuit, including the nature and seriousness of the suspected offense, population density of the area, traffic and the performance and handling capabilities of the trooper's and suspect's vehicles. Weather conditions also play a role, as does whether police know the identity of the suspect.

He said if troopers headed into the city in pursuit of a suspect, dispatchers would call ahead to tell the city Police Department what was going on. He said pursuits rarely take troopers into Baltimore or Washington because "it is risky."

It was not clear where the trooper was coming from and why he was traveling through downtown to get to the Golden Ring barracks, which are several miles northeast of downtown. "That's something we're following up on," Shipley said.

City Councilman Brandon Scott said the tragedy could have struck anyone walking outside City Hall that day.

"It's awful," he said. "It's a beautiful day. You're walking outside. This shouldn't happen to anybody."

Hersl's sister immediately drove to Shock Trauma, where Baltimore fire paramedics had taken him, according to brother-in-law Charles Shott. She met Daniel Hersl, a Baltimore police officer and Matthew Hersl's brother, who was the first family member to arrive in the emergency room.

"We just heard the car struck a median and hit Matthew," Shott said. "I'm just hearing bits and pieces. My wife's all shook up."

Shott said Hersl was a "good man, a good guy."

He was not married and did not have any children but left behind four brothers, his sister and his mother.

"He got along with everybody," Shott said.

Baltimore Sun reporters Justin George and Carrie Wells contributed to this article.