Seattle police say a reward of as much as $40,000 is being offered for information that leads to the arrest and prosecution of those responsible for the slaying of 39-year-old Officer Timothy Brenton. The training officer was hit as he sat in a car reviewing a traffic stop with Student Officer Britt Sweeney.

Meanwhile, a man police documents described early Sunday morning as a "person of interest" in the killing of a Seattle police officer on Halloween night pleaded not guilty Monday to a charge of obstruction. He has been ordered held on $15,000 bail -- an amount much less than the $75,000 city prosecutors requested.

According to police documents, the man on Friday threatened a King County Jail sergeant who had been assigned to his pending case. The man told the sergeant he might have to "take someone out" and talked of killing a Seattle police officer and corrections officers, investigators said.

The man was arrested at his home on Friday, but made bail on Saturday. Dispatchers told officers that the man had again made threats as he left the jail, documents said.

Even though court documents have identified the man as a person of interest in the case, investigators said they have not narrowed their search to just one person.

"We've talked to scores of people - people who have made threats, either directly or indirectly to law enforcement, not only Seattle police officers, but others - and we're pursuing leads there," said Asst. Police Chief Jim Pugel.

After Officer Timothy Brenton was shot and killed Saturday night, police went to look for the man as a person of interest and found him in a car outside his apartment in South Seattle.

Officers say he refused to step out of the vehicle, had to be forcibly removed and was booked for investigation of obstruction. Seattle police would not comment, except to say their investigation into Brenton's death is ongoing and they have not ruled anything out.

In the briefing to the council Seattle Police Interim Chief John Diaz said investigators are looking at a massive amount of video gathered from the area.

"We pulled every in-car video camera from all the vehicles that worked in that area, going back several hours. We're also checking all the videos from all the businesses," and red light cameras, he said.

Brenton was a nine-year veteran of the department, but his roots - in the region and in law enforcement - run much deeper. He graduated from West Seattle High School in 1988. His father and his uncle are both retired Seattle police officers.

Brenton joined the Seattle Police Department after working as an officer in La Conner. He was most recently a part of the East Precinct Anti-Crime Team -- a job that made him a hero to the community he served.

The fallen officer is survived by a wife, an 11-year-old daughter and an 8-year-old son.

Flags throughout the city are flying at half-staff in honor of Brenton.

A candlelight vigil and service honoring the fallen officer were held at St. James Cathedral on Monday night.

"Any time we lose a police officer it's a tragedy, but this loss is particularly painful because Officer Brenton and his partner, Officer Britt Sweeney, were ambushed," said Seattle City Council member Tim Burgess.

Diaz said information is already coming in on the department's tip line (206-233-5000), and Clear Channel Communications has donated four billboards that will be used to recruit more tips.

Sweeney is recovering at home as she works with investigators.

As part of a wide-ranging investigation, police are looking for any possible connections between the shooting and the Oct. 22 torching of four police vehicles at a Seattle maintenance yard. Police spokesman Sean Whitcomb says the timing and sophisticated nature of both attacks warrant scrutiny.

Interim Chief John Diaz told a City Council briefing Monday that the slaying was a "hit on law enforcement."

"We're going to do everything in our power to find this person," he said. "Every local and state agency is helping."