SONOMA COUNTY, Calif. -- Investigators from the Sonoma County Sheriff's Department recently returned from New Mexico, where they looked for evidence to solve a 5-year-old killing.

Authorities were looking into DNA evidence that might prove whether Joseph Henry Burgess shot to death Jason Allen and Lindsay Cutshall on a beach in Jenner in 2004.

Burgess was killed on July 16th during a shootout with a New Mexico deputy sheriff in the mountains above Albuquerque. Burgess was suspected of breaking into numerous cabins in the area. The deputy also was killed during the shootout.

Sonoma County Sheriff's investigators are trying to match a DNA sample from Burgess to a beer bottle found on the beach in Jenner after the killings. The bottle may or may not have belonged to the killer.

"In the end, as much as we'd like to positively say this person did do this or this person didn't do this, "in reality we may never be able to say that," said Captain Matt McCaffery of the Sonoma County Sheriff's Department. A DNA match would put Burgess on the beach in 2004.

The similarities of the killings in Jenner to one in 1972 in British Columbia raised a red flag. In that case, two people sharing a sleeping bag on a secluded beach were each shot once in the head. A fingerprint at the scene identified Burgess as the killer.

Investigators said Burgess was a religious fanatic who was strongly against premarital sex.

Until fingerprints identified Burgess as the man killed during the shootout, authorities didn't know that Burgess was still alive.

New Mexico authorities said the gun Burgess used to kill was registered to David Eley. Eley disappeared while camping in 2006. Investigators now believe Burgess may have killed him.