(CNN) -- A San Antonio police officer was fatally shot during a traffic stop Sunday in what the department's chief described as a targeted killing similar to recent police shootings in Dallas and Baton Rouge, Louisiana.
Detective Benjamin Marconi, a 20-year veteran of the department, was shot in his patrol car outside police headquarters, Chief William McManus said Sunday in a news conference. Marconi was 50 years old.
"[When] most families will be celebrating the holidays SAPD will be burying one of its own because of an ultimate act of cowardice by a suspect who will be caught and brought to justice," McManus said.
Police asked the public for help finding the suspect, whom McManus described as a slim black man in his 20s or 30s in a gray shirt and gray pants. He is believed to have fled the shooting scene in a black sedan with chrome rims and dark covered windows.
"We consider the suspect to be extremely dangerous and a clear threat to law enforcement officers and the public," he said.
The shooting occurred in front of police headquarters before noon, McManus said. Marconi had just pulled over a driver on the south side of the building and returned to his patrol car to write a ticket when a man pulled up behind him.
The man walked up to the patrol car driver's side window and shot the officer in the head, McManus said. The man then reached through the open window and shot him a second time, McManus said.
After the shooting the man returned to his vehicle and drove away.
Earlier Sunday, McManus likened the shooting to recent deaths of police officers in Dallas and Baton Rouge, Louisiana.
Both of those incidents followed police-involved shootings of civilians that triggered protests nationwide. Police are investigating motive in this case, including a possible connection to a Sunday morning officer-involved shooting in Dallas, McManus said.
"Unfortunately, like Dallas, like Baton Rouge, it's happened here," he said.
"It's always difficult, especially in this day and age where police are being targeted across the county," he added. "Hopefully we'll solve this one real quick, and if this individual is a danger to more police or anyone else we will try to get him off the street as soon as we can."
San Antonio Mayor Ivy R. Taylor condemned the shooting and called for patience while the investigation continues.
"I want to extend my deepest condolences to the family of the officer killed outside police headquarters today as well as to our entire police force. This type of crime cannot and will not be tolerated. I ask for the community's thoughtfulness and patience as the investigation continues and SAPD searches for the suspect," Taylor said.