On July 5th 1970, three men Thomas Victor Dolan (17) of Manhattan Beach, Thomas Hayes (19) of Hermosa Beach and Homer Clyde Shadwick (19) of Saginaw Michigan were discovered by a passer by on a beach in Santa Barbara, that straddled the University of California Santa Barbara building. Two of the young men had succumbed to their injuries, while the third Thomas Hayes had been rushed to hospital in nearby Goleta in critical condition, after the three appeared to have been subjected to a frenzied attack with a bladed weapon while camping out in their sleeping bags on the night of the July 4th 1970. Fortunately for Thomas Hayes, he survived the brutal assault. The three had hitchhiked back from fireworks celebrations at Candlestick Park in San Francisco. The assailant/s took none of the victims possessions in an apparently motiveless attack.   

This attack came approximately four months after the Hood and Garcia Murders, who on Saturday February 21st 1970, 11 miles east of these attacks, fell victim to a knife wielding assassin on a quiet retreat of East Beach, Santa Barbara, a crime some believe had the hallmarks of the notorious Zodiac killer, who terrorized Northern California in the late 60s and early 70s. As did the murders of Robert Domingos and Linda Edwards on June 4th 1963, a couple were brutally gunned down while fleeing for their lives from a remote beach, situated 3.32 miles east of Gaviota State Park and alongside Highway 101, approximately a five-hour drive from Vallejo, California.
Detectives drew parallels between the Sleeping Bag Murders and the Hood and Garcia slaying, yet to this day no arrests have been forthcoming in either case.
Approaching her 80th birthday in 2004, Donna Dolan, the mother of Tommy Dolan asked police to re-open the case, fearing she may never see justice for her son. “[Investigators] have the hatchet,” Donna Dolan said. “There was also a knife or a sword that have never been in the evidence room, but they know what it was because of the wounds. Any blood was from [Tommy Dolan and Homer Shadwick] – the perpetrators weren’t hurt in any way because the boys were sleeping in sleeping bags and they couldn’t even defend themselves … I was told by the detective at the Dept. of Justice that he would use anything he could find some DNA on.” Read more at the Daily Nexus.

The Hillside Daily News, Michigan July 14th 1970
'Detectives said Sunday the victim of a double slaying on a beach a week ago has been identified as an Army deserter carrying a friend’s identification so he wouldn’t be caught. Homer Clyde Shadwick, 19, of Saginaw, Michigan., was hacked to death as he slept on a University of California campus beach with two acquaintances after attending a Fourth of July fireworks display. A California youth also was slain, and another has been in critical condition since the attack. Officers first thought Shadwick was Larry Steve Hess, 20, of Lagrange, Indiana, because that was the name on all identification cards in his wallet. Fingerprints received from Florida, where Hess had an arrest record, proved the victim was not Hess. Final identification was made after the FBI was able to match the victim’s fingerprints with Shadwick’s.
Shadwick’s sister was located in Seaside, California, and she identified the body. Detectives also found Hess living at the home of Shadwick’s sister and her husband. Hess said he was unaware he had been listed as the victim. Hess told officers he and Shadwick lived together in Saginaw before hitchhiking to the coast in June. Shadwick was listed as a deserter from Ft. Lewis, Washington, since October. He and Hess closely resembled each other, deputies said. Detectives did not know how Shadwick met up with Thomas Victor Dolan, 17, of Manhattan Beach, and Thomas M. Hayes, 19, of Hermosa Beach, but think they met while hitchhiking. The trio apparently decided to spend the night on the beach after watching a fireworks display. The bodies of Shadwick and Dolan, beaten and cut up by a knife and a machete­ like weapon, were found Sunday morning. Hayes has not fully regained consciousness. No arrests have been made in the case.'

​7/6/70 The Press-Courier
Two Youths Found Hacked to Death SANTA BARBARA, Calif. (AP)-
An early morning beach stroller found two young men hacked to death in their sleeping bags and a third critically injured with
multiple head gashes. Investigators said the three apparently were attacked as Ihey slept on a beach next to Ihe University of California at Santa Barbara.
The blood-spattered bodies were found al sunup Sunday. The victims were identified as Larry Sieve Hess, 20, of La Grange,
Indiana, and Thomas Victor Dolan, 17 of Manhattan Beach, Calif, Thomas M. Hayes, 19, Hermosa Beach, Calif, was reported in crilical condition but improving at Goleta Valley Hospital after five hours of surgery. Sheriff's deputies said Hayes remained unconscious and was under light security at the hospital. Hayes' parents said the youths were on a trip lo San Francisco.
Officers said the death weapon apparently was a halchel or meat cleaver. The victims still had money and watches, officers added.
Two other persons were killed last Feb. 22 on a Sanla Barbara County beach, 20 miles from the latest murder scene. John Franklin Hood, 24, of Oxnard, and Sandra Garcia, 19, of Sanla Barbara, were beaten and slabbed to death. Their murders remain unsolved.

Experimenting with the idea that a silencer was used in the commission of the Blue Rock Springs attack and furthermore a silencer or modified compressor was either used or carried during all four attacks of the Zodiac Killer.

Examining the most likely hot spot, the Zodiac Killer returned to after his murderous acts of evil, to narrow down a location to the small town of Benicia.