UPDATED 07/08/11 11:10 a.m.

CHICAGO (CBS) — There is a possible break in the murder last year of a Chicago Police officer, who was gunned down as he polished his new car outside of his home.

As CBS 2’s Susanna Song reports, multiple sources say police are questioning a 24-year-old prison inmate in the murder of Officer Michael Bailey, 62, who was shot and killed on July 18, 2010.

The inmate is serving a sentence downstate on vehicular hijacking and weapons charges, according to a Chicago Tribune report.

The inmate is not being labeled officially as a suspect. All police would say Friday morning was that progress is being made in the investigation.

LISTEN: Newsradio 780’s Mary Frances Bragiel reports

Bailey, a 20-year veteran of the Police Department, had just finished an overnight shift guarding the home of since-retired Mayor Richard M. Daley. He was still in uniform as he returned to his home in the 7400 block of South Evans Avenue in the Park Manor neighborhood.

As Bailey polished the new Buick Regal that he had bought himself as a retirement gift, someone came up and shot him with a handgun. He died of his wounds.

Bailey’s retirement was only a month away at the time.

Just a few months ago, Bailey’s daughters told CBS 2’s Kristyn Hartman they won’t have peace until they find out who killed their father.

“We have no idea why nobody will come forward,” said Danielle Drayton, Bailey’s stepdaughter.

“All this has shown me how real the code of silence is, and how real death is,” said Officer Bailey’s daughter, Jada Bailey.

A couple of weeks after the murder, Bailey’s family moved out of their house and had it boarded up. Meanwhile, a reward of more than $130,000 was offered, but the case was never solved.

Residents of Bailey’s old neighborhood on Friday hoped the latest development would lead to charges in the case.

“Hope they get him, whoever did it – man, woman or child; whoever,” said Park Manor resident Robert Cook. “I thought they would (have a suspect) by now because I asked the policemen – you all ain’t got him yet?”

Cook said even last week, officers stopped by the neighborhood to talk to his son and other neighbors, in a sign that the investigation remains ongoing.

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