SEATTLE -- Detectives are acting on a flood of tips as people come forward with information on the shooting ambush of two police officers on Halloween that killed one officer and wounded another.

"We are receiving information -- I'm overwhelmed at the amount of information being forwarded by thoughtful people, whether they're anonymous or not," said Assistant Seattle Police Chief Jim Pugel.

The assistant chief said it appears the shooting of Field Training Officer Tim Brenton and Officer trainee Britt Sweeney was planned as a political statement against police.

Police are questioning a man who they are calling a person of interest in the shooting.

Awaz Maki Madow, 25, was charged with making threats to two King County Jail deputies before he bailed out on Halloween.

Deputies noted Madow's violent threats hours before Officer Brenton was killed in the ambush of gunfire.

"Madow said something about killing an SPD officer and a corrections officer. He ended the conversation by saying that he would come back and 'tear up you and your partner,'" a police report said.

Madow was spotted in his car after the shooting, four miles away from the scene. Police said he resisted arrest and is back in jail, pending more charges.

Madow pleaded not guilty Monday to a charge of obstruction. More details

Pugel said detectives are tracking people with similar motivations.

"We talked to scores of people. People who have made threats, either directly or indirectly to law enforcement, not just Seattle police officers, but others, and we're pursuing any leads there," said Pugel.

Pugel said some tipsters claim the officers' shooting may be connected to the fire-bombing of four Seattle police vehicles in a maintenance yard on Oct. 22. More details

Pugel said timing and circumstances between the two incidents are similar.

"It was bold. It's not seen often, certainly not in the Northwest, and because it happened contemporaneously with (the shooting), we would be foolish if we didn't look at that," said Pugel.

In addition, detectives said the car involved in the attack may have been damaged by Officer Sweeney, who fired as many as 15 gunshots at the side and back of the car as it sped from the scene.

Meanwhile, a memorial with bunches of flowers, flags and prayers at the shooting scene arrived as visitors streamed by throughout the day. See images

Police officers and citizens gathered there for a candlelight vigil Monday night, as Central District community leaders expressed outrage at the violence and showed solidarity with the police department, asking for the public's help to catch the killer.

The vigil quickly grew and more than 100 people attended to pay their respects.

Police ask that anyone with information about the shooting is asked to call the Seattle Police Department Tip Line at 206-233-5000, the Seattle Police Homicide Unit at 206-684-5550 or 911. Those who wish to remain anonymous can call Crime Stoppers at 206-343-2020 or send a text message to Crime Stoppers by texting tip486, then send to 274637. Calls are taken 24 hours a day.

In another effort to find Officer Brenton's killer, Clear Channel donated four billboards located in Kent that show information where tips can be left.

The Seattle Police Officers Guild, along with contributions from citizens and Crime Stoppers are offering a total reward of up to $40,000 for information that leads to the arrest and prosecution of those responsible.

The memorial service for Officer Brenton is scheduled for Friday, Nov. 6, at 1 p.m. at Key Arena.