Cheyenne Police Chief Brian Kozak says investigators have identified "several suspects" in a double homicide that happened at a Cheyenne business last summer.

But he says police can't move forward on the case until  they get back DNA evidence from a Colorado laboratory--and no one seems to know when that might happen.

The chief says police have seized more than 100 pieces of evidence in the murder of 67-year-old Dwight Brockman and 76-year-old George Manley last July.

Kozak says that while Wyoming has a crime laboratory capable of handling basic DNA tests, the items sent to the Colorado lab will be subjected to a cutting-edge DNA "vacuuming" procedure that is up to 10 times more effective than traditional DNA tests.

Kozak says that while solving the Cheyenne double-homicide is a top priority for his agency, that isn't necessarily the case for the Colorado lab, which is dealing with high-priority investigations from across that state and the region..

"We're really pushing them to get it done, and we're waiting," Kozak says. But he adds local police haven't been told when the results from the Colorado lab might become available.

In the meantime, he says police don't have the evidence to make an arrest in the case.

Brockman and Manley were shot to death during an apparent armed robbery at The Coin Shop on West Lincolnway on July 20, 2015. Brockman was the owner of the business and Manley was a frequent customer.

The crime occurred shortly after a Cheyenne Frontier Days pancake breakfast was held, which meant city streets were jammed with traffic and large crowds of visitors were in Cheyenne.