Updated: 11/24/10 10:25 p.m.

CHICAGO (CBS) — Chicago police said Wednesday that they’re talking to dozens of people about the murder of police officer David Blake.

But as CBS 2’s Dana Kozlov reports, so far there are few clues in his shooting death.

Blake, 45, was found shot to death in his personal car on the 2900 block of West Seipp Street Monday night. Sources said he’d been shot in the head five times, an unlit cigarette still in his mouth. Police said he had his gun and wallet, and thus, robbery is not a likely motive.

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His murder has shaken those who knew him and respected him. They called him a dedicated SWAT team member who loved his job.

“It was unbelievable. I still didn’t believe it. Then my sergeant came and picked me up at the house and we went over to the scene,” Blake’s partner, Police Officer Norell Liboy said.

Blake was off-duty when he was killed, parked more than three miles from his home.

Police sources said they don’t know why Blake was on that street.

Liboy said he’d just seen his partner earlier that day and everything seemed normal.

“Monday we were together for furlough selections, picking our vacations for next year. And it was just another day,” Liboy said. “We were just poking jokes at each other on the way up and the way down. I never knew he was actually planning a vacation … he was going on vacation this week.”

Police sources said Blake, a 15-year Police Department veteran and department football team member, knew a lot of people and they are talking to many of them about the case.

As CBS 2’s Kristyn Hartman reports, a squad car was outside Blake’s boyhood home on Wednesday. And an even bigger police presence was outside and inside his residence.

Neighbors watching say there has been a lot of police activity in the area over the last 24 hours, including squad cars and detectives removing items from Blake’s apartment, including a computer.

Officer Theodore Browning, who lives on the street where Blake was killed told CBS 2’s Mike Puccinelli that he saw someone run from the car after the shooting. Browning called 911.

Sources say he is one of the many people detectives are talking to about the case; one Blake’s partner describes as surreal.

“Something I never thought would happen,” said Officer Liboy. “These few days have rolled into each other. It’s heart-wrenching.”

Now everyone is waiting for answers.

Officer Greg Zaragoza said it was “frustrating and painful” to hear Blake had been killed.

“I desire to have questions answered, but, hopefully all that stuff will work itself out here shortly,” Zaragoza said.

It is possible Blake knew his killer, because none of his car’s windows were broken – indicating that the person who pulled the trigger might have been in the car with him.

Sources said that, despite the fact that friends said Blake didn’t smoke, it doesn’t appear the cigarette was planted on his body after his death.