Investigators: Two guns used in Oklahoma girls' killings

"Typically you don't have one person using two weapons," said Oklahoma State Bureau of Investigation spokeswoman Jessica Brown. Further details on the weapons were not released.

OSBI Special Agent Ben Rosser said in an afternoon news conference that investigators still have no suspects and no theory for why the crime occurred.

"Still no motive, and I hate to say that, but this could be some kind of random thrill killing, it could be an attempted abduction, it could be somebody that just for whatever reason had a personal motive, maybe mistaken identity or possibly they did interrupt something down near the bridge, we just don't know," Rosser said. "All things are being considered at this point."

Each girl was shot multiple times in the head and chest, according to the state medical examiner's office. Their bodies were found on a county road near a bridge.

Although a complete autopsy report has not been finished, investigators have said sexual assault appears unlikely because the girls were clothed and had only been missing for half an hour.

The bodies of Taylor Paschal-Placker, 13, and Skyla Whitaker, 11, were discovered Sunday by Taylor's grandfather about a quarter mile from his house near Weleetka, about 70 miles south of Tulsa.

Investigators were examining evidence, including tire tracks, shell casings, ballistics and shoe prints for any possible leads.

"I could walk down Main Street in Weleetka and maybe pass the individual and I wouldn't know it right now," Rosser said. "Hopefully sometime we'll develop the information and be able to say we believe this individual, or we know this individual or individuals are responsible and maybe we can put a face to what we're looking for."

"There's no indication that their friends and families are involved, but we're just keeping an open mind on anything right now."

A reward for information leading to an arrest in the case was increased Wednesday to $25,000.