California investigators are tracking down more than 150 tips flooding into their agency about a young couple found shot to death in their sleeping bags on a remote beach.
There are similarities to a Scottsdale couple's slaying at a campground in October, but nothing solid enough yet to warrant the FBI's involvement, Yavapai County sheriff's spokesman Lt. Steve Francis said.
"There would have to be a strong indication that these two things were definitely tied and we were looking at a single person crossing state lines and doing this," Francis said.
Lindsay Cutshall, 23, and Jason Allen, 25, were found Wednesday near Jenner, Calif., in Sonoma County. Autopsies show they were shot in the head at close range.
Authorities have ruled out a murder-suicide because no murder weapon was found, and there was no evidence of robbery or sexual assault.
Lisa Gurrieri, 19, and Brandon Rumbaugh, 20, were found Oct. 19 in a remote area near Interstate 17 about five miles south of Sunset Point campground. They had been shot in the head in their sleeping bags.
Both cases are unsolved. Sonoma County sheriff's Lt. Roger Rude said detectives have contacted Yavapai County authorities about the similarities.
"Our department and their agency has exchanged information about the investigation," he said.
"At this stage of the game, any information about the case is helpful, " Rude said.
Phoenix FBI agent Susan Herskovits confirmed that the agency has not been asked for assistance through its Violent Criminal Apprehension Program. The program was created partially to target serial killers, Herskovits said. It is a nationwide crime database designed to collect and analyze crimes of violence and compare them against against other crimes for possible similarities.
- The Associated Press contributed to this report.