Arlington County police have made two arrests in the killing of Carl Diener, who was stabbed in 2009 as he walked to his job at a Clarendon gym.

Roger K. Clark III, 20, of Severn was arrested Wednesday and Javon Martin, 24, of the District was arrested Friday. Both are awaiting transfer to Virginia.

Diener, 57, was found at 2:50 a.m. Dec. 29. Beaten and stabbed, he was found lying on the street in the 3200 block of North 13th Street in Clarendon.

Police did not immediately disclose a motive for the killing. Det. Crystal Nosal said investigators do not believe Diener knew his attackers. She also said the killing was not a hate crime, and it did not involve gang activity.

“He was just walking to the gym,” Nosal said.

Arlington County Police Chief M. Douglas Scott said he was pleased with the investigation.

“It illustrates that there are no ‘cold cases’ in Arlington,” he said. “We continue to investigate crimes long after they occur.”

Diener’s family, friends and neighbors raised $25,000 for information that would lead to the arrest and conviction of his killer. They also held several vigils and benefits in his memory.

But Nosal said she thinks the $25,000 will not be claimed.

“I don’t think there was a tip in this case,” Nosal said. “I think it was evidentiary.”