William Alexander Zepeda, the final suspect in the 1998 execution-style slayings of two restaurant workers in Lawrenceville, had eluded capture for 13 years.

Gwinnett County District Attorney Danny Porter never expected to be able to prosecute him.

The last Porter heard from the FBI, back in 2004 or 2005, was that Zepeda was imprisoned in El Salvador.

"To be honest I never expected to see him," Porter told the AJC Tuesday. "We don't have an extradition treaty with El Salvador. He could have been laying on the beach."

But Zepeda returned to the United States at some point and on Monday night, the FBI arrested him in Austin, Texas. The Safe Streets Task Force picked up Zepeda "during an alien drug sweep," the FBI said.

Now Zepeda, 37, awaits extradition to Gwinnett County. He's charged with two counts of murder and armed robbery.

Joaquin Enrique Arevalo is on death row for the crime. His brother, David Arevalo, pleaded guilty to armed robbery in 2000 and is serving a 20-year sentence.

Joaquin Arevalo worked at the now-closed Tanner's Rotisserie Chicken on Gwinnett Drive, but was fired for refusing to take out the trash, according to prosecutors. He decided to rob the store and was helped by his older brother, David, and Zepeda, prosecutors said.

David Arevalo, a Tanner's dishwasher, got to work before the restaurant opened on April 6, 1998 and propped open the back door to allow his accomplices to enter, prosecutors said.

Restaurant manager Marc Ratthaus, the only other employee there, was forced into the cooler by Joaquin Arevalo and Zepeda, Porter said. Joaquin Arevalo shot Ratthaus in the back of the head. Ratthaus lived for three hours.

On their way out after the robbery, Joaquin Arevalo and Zepeda encountered cook Adolfo Gonzales, a married father of two. The cook recognized Joaquin Arevalo, who shot him in the back of the head.

David Arevalo implicated Zepeda and told police his younger brother turned the robbery into a murder.

Prosecutors say Joaquin Arevalo wore a stocking mask to hide his identity. But when his co-workers recognized him, he shot them.

Porter said Zepeda was there during the killings and was a party to the crimes.

The District Attorney's office is trying to contact the families of the victims to notify them of Zepeda's arrest.

"We have all the evidence in the case," Porter said. "We can be prepared to try it. So I'm glad we're finally able to bring him back."