Seattle, Washington (CNN) -- Thousands of police and residents will honor Seattle Police Officer Timothy Brenton on Friday with a long procession of automobiles that will wind through the city before the slain officer's funeral.
A flag of a Seattle police badge is also being flown from the city's iconic Space Needle in tribute to Brenton.
Brenton, a training officer, died in a hail of bullets Saturday when a car pulled up to his parked patrol car and opened fire. Brenton's partner, a trainee, was slightly wounded and fired her weapon at the shooter's car as it drove away.
As his colleagues prepared to honor Brenton they continued to hunt for his killer.
Police have no suspects but Thursday released pictures of "a vehicle of interest" that dashboard cameras in other police patrol cars recorded near the scene of the shooting Saturday.
Police described the car they are looking for as either a white or beige 1980 to 1983 Datsun 210.
Assistant Seattle Police Chief Jim Pugel, in a Thursday press conference and a statement released to the media, said the department is compiling a profile that might describe the shooter.
"He likely has experienced a significant personal crisis in the recent past. This event may have been the death of a loved one, loss of job or status, divorce, financial hardship, or other failure," Pugel said.
"His skills in weapons use and close-quarter techniques suggest prior training. He has likely practiced a great deal with weapons and those around him will note his abilities and interest in them," he said.
Pugel said police have not discounted the possibility that the shooter had help or was part of a group targeting police.
Officials said they continue to investigate whether the shooting is linked to a recent fire bombing of police vehicles.
In October an unknown person torched four vehicles at a police maintenance yard, police say. But the events may not be related, police spokesman Mark Jamieson said, noting, "It's an enormous escalation to go from destroying property to taking a life."