(CNN) -- As a reward for information rose to $85,000 Wednesday, the president of the police union in Seattle, Washington, said no one in the city is safe while the killer of an officer is on the loose.
"The citizens are outraged," Police Guild President Richard O'Neill said in an interview with CNN affiliate KIRO. "This does not happen in Seattle."
Law enforcement officials are vowing to catch whoever is responsible for fatally shooting Officer Timothy Brenton and injuring a student officer as they sat in a parked patrol car.
Brenton, 39, a field training officer, was reviewing details of a traffic stop with student officer Brit Sweeney Saturday night when a vehicle rolled up next to the squad car shortly after 10 p.m., authorities said
People inside the vehicle fired several shots into the squad car, killing Brenton and wounding Sweeney, according to police.
According to transcripts released Tuesday, Sweeney called in reporting "shots fired." She sobbed, then a few seconds later said, "My partner is dead."
A shot grazed Sweeney, tearing through her uniform and protective vest, Police Chief John Diaz said at a news conference Sunday. She fired at the attackers' vehicle, but police didn't know whether any of her bullets struck it, Assistant Chief Jim Pugel said.
Pugel called the attack an "assassination," but said there had not been a threat made against Brenton.
The attackers' car was a white, light blue or silver subcompact or compact vehicle, Pugel said.
Department spokesman Mark Jamieson said police are reviewing dashboard camera video from patrol cars that were nearby.
"We don't have a suspect's car [identified]. We have a general description of a car that was in the vicinity when this crime occurred," Jamieson said.
The shooting was the first intentional homicide of a city police officer since 1994, Seattle Mayor Greg Nickels said.
Nickels described the shooting as "cold-blooded."
"We will not rest until the assailant is brought to justice," Nickels said at Sunday's news conference.
Crime Stoppers boosted its reward to $85,000 for tips leading to an arrest and conviction in the case, Deputy Chief Nick Metz said.
Assistant Chief Pugel read a handwritten letter from Brenton's Family to CNN affiliate KING: "We know that Tim would be honored and humbled by the limitless support that has been provided at this difficult time. We sincerely thank you for the generous emotional support, thoughts, and prayers."
Brenton was married with two children, 11 and 8, Metz said.
"The family is obviously extremely devastated," Metz said. "The family, obviously at the beginning, when he left for work, certainly didn't anticipate that we were going to come knocking on their door."
Metz told KING, "For a lot of our officers, this is the first time they've had to deal with one of their own being killed in the line of duty like this."
Brenton served on the force for nine years, police said. His father and uncle are retired Seattle police officers.