JACKSONVILLE, Fla. -

Police are hoping that an anonymous $10,000 donation shakes loose some information about the slaying of a construction worker killed during a robbery attempt last month on Jacksonville's Southside.

Clifford Backmann, 56, was working alone finishing some construction on an office condominium near the intersection of Philips Highway and J. Turner Butler Boulevard on Saturday morning, Oct. 10, when someone shot him. He was able to call 911 and give some details before he died, but not enough to catch his killer.

"We're all standing here today still in shock, still not understanding why this happened," the victim's son, Ryan Backmann, said. "He wasn't making a whole lot of money on Saturday cleaning up an empty office complex. He was doing it because a friend asked him to -- that's the kind of person he was."

Police said the shooting was in a relatively busy area, near hotels and restaurants and along a bus route.

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The donation adds to Crime Stopper's own $1,000 reward.

"This is a brazen act in the middle of the day -- middle of the morning,"Jacksonville Sheriff's Office Assistant Chief Tom Hackney said. "We're hoping that somebody either saw something or has some knowledge that occurred after the fact. This $11,000 is enough to generate somebody talking.

Ryan Backmann said his father had a habit of clipping information about victims of crime and show them to his co-workers to raise awareness about violent crime.

"He knew there was a family mourning their loss, and now we are that family," he said Monday. "Everybody out there has a dad. Put yourself in my position ... think it's your dad."

Anyone with information is asked to call Crime Stoppers at 866-845-TIPS. Tips can be e-mailed to rewards@fccrimestoppers.com, left on the Web site, or by text message by sending "TIP326" plus message to "CRIMES."

Callers can remain anonymous and be eligible for the reward.