Diener, 57, was found at 2:50 a.m. on Dec. 29, 2009, lying on the street in the 3200 block of North 13th Street in Clarendon; he had been beaten and stabbed. He had been on his way to open the nearby Sport & Health Club.
Police did not disclose a motive for the killing. Detective Crystal Nosal, a police spokeswomen, said investigators do not believe Diener knew his attackers. She also said the killing was not a hate crime and did not involve gang activity.
“He was just walking to the gym,” Nosal said.
Each morning he worked, he would walk about a mile from his Lyon Village home to the health club, friends said.
Diener’s sister, Patti Diener Lough, said many people told her that an arrest in the case would bring her closure.
“It doesn’t bring closure. Nothing can bring Carl back,” she said. “Hopefully it will get some criminals off the streets and it will bring us answers.”
But she added that the answers will be painful because she will have to relive his last moments.
Lough said she felt “somewhat consoled” that two people were arrested, because her brother was 6-foot-4 and very athletic and she believed he would have fought off a single attacker.
“Carl was a strong, powerful guy,” Lough said. “There had to be more than one guy. It just didn’t make sense any other way.”
Diener loved racquet sports, cycling and nutrition. After retiring from his government job in 2008, he worked at two health clubs and dedicated himself to physical fitness.
Arlington Commonwealth’s Attorney Richard E. Trodden said more details of the crime will come out at a preliminary hearing for the men, which has not yet been scheduled.
Police Chief M. Douglas Scott said he was pleased with the investigation and the determination of the detectives.
“It illustrates that there are no ‘cold cases’ in Arlington,” Scott 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 the arrests came from a tip in this case,” Nosal said.
The Lyon Village Citizens Association responded to the killing by identifying and fixing 90 broken street lights and distributing 1,000 fluorescent bulbs so residents could keep their porch lights on at night.
“Carl was a friend and tennis partner of many in our neighborhood, and we hope that these arrests will lead to convictions,” said H.K. Park, president of the association. “Our neighborhood lost some innocence after his death on North 13th Street, but we banded together by collecting tips for the police and by raising money for a reward.”