ARLINGTON (CBSDFW.COM) - Arlington police say thorough police work and a high-tech database have cracked a 3 1/2-years-old, unsolved double homicide that has haunted investigators.
"It was a real horrific crime," Lt. Chris Cook with the Arlington Police Department. "It was probably one of the worst ones we've seen in a while."
In their ransacked apartment, police found the bound bodies of Long Nguye, 72, and Huong Ly. Both, 63, were asphyxiated. Police also found a marijuana cigarette.
"So we processed that process which included sending that off for analysis and they were able to get a DNA profile from the cigarette paper," Cook said.
More than three years later Willy Guillory, 20, had a DNA sample taken after he was jailed for horse theft. It matched DNA from the crime scene. Guillory was 16-years-old at the time of the murder.
Friends of the victims still have unanswered questions since police haven't established a motive for the murders.
"Why?" family friend Cindy Dao asked. "Because you know he was 16 and they were in their 70's and 60's and if you needed money, if you needed help they would've helped him."
For family of the victims the arrest ends years of fear.
"After that it was just watching their backs," Dao said. "Being stressed out... they don't know if they're going to be the next target or not. And it's stressful. And they have teenage kids and not knowing who is after them -- if somebody was after them."
Police say the break was a combination of old fashioned thorough police work and high-tech DNA data collection. "It just goes to show you, you see the stuff on the television and on crime shows but it happens in real life," Cook said.