LITTLE ROCK — The FBI agreed Wednesday to help an Arkansas prosecutor unlock an iPhone and iPod belonging to two teenagers accused of killing a couple, just days after the federal agency said it had gained access to an iPhone linked to the gunman in a mass shooting in California.

Faulkner County Prosecuting Attorney Cody Hiland said the FBI agreed to the request from his office and the Conway Police Department on Wednesday afternoon. A judge Tuesday agreed to postpone the trial of 18-year-old Hunter Drexler so prosecutors could ask the FBI for help. Dexler's trial was moved from next week to June 27.

Drexler and 15-year-old Justin Staton are accused of killing Robert and Patricia Cogdell at their home in Conway, 30 miles north of Little Rock, in July. The Cogdells had raised Staton as their grandson.

The FBI said Monday that it had gained access to an iPhone belonging to Syed Farook, who died with his wife in a gun battle with police after they killed 14 people in San Bernardino in December. The agency hasn't revealed its method.

Hiland said he could not discuss details of the murder case in Arkansas but confirmed the agency had agreed less than a day after the initial request.

"We always appreciate their cooperation and willingness to help their local law enforcement partners," he said.

Read Thursday's Arkansas Democrat-Gazette for full details.