"Where Brian ran around the blind side of this backyard and was shot, there was a shoelace found on the ground, a new shoelace right out of the package and a loop on it," Biondi, 81, said. "That was one of the things he did, he used a shoelace for binding (victims)."
Biondi said he feared for years that the suspect in the case was dead or in prison undetected, and that he was ecstatic when he heard this week that an arrest had been made.
"Oh, God, I thought a lot about this case over the years ...," said Biondi, who has solved some of the Sacramento area's most notorious cases, including the "Thrill Killer," "Vampire Slayer" and "I-5 strangler."
"I've worked other serial killer cases, but not a serial, serial murderer," he said. "This guy's a multiple serial murderer."
Other murders in the case may be solved by nearly 40-year-old DNA evidence salvaged from crime scenes in Orange and Ventura counties, the same samples used to track DeAngelo down.
Dr. C. Peter Speth, the former assistant medical examiner in Ventura County, said he still remembers the shocking scene at the home of Charlene and Lyman Smith, who were found bound and bludgeoned in their bed.
"It was one of the most horrible scenes that I've encountered in my 35 years," Speth said. "It is something that has left a terrible mark in my memory, going to the scene and seeing them battered to death by a log in their bed with the blood spattered on the wall. I'll never forget it."
Speth said the fact that DNA from that case remains is only because he has a habit of assembling two DNA kits at each scene. The first, used by the crime lab, has since been used up or discarded, he said, but he had stashed the second in a freezer just in case.
"I was so relieved when I heard that they found the killer and he was still alive and will have to go to court," Speth said. "I was so relieved for the families."
Former Sacramento County Sheriff John McGinness worked angles of the East Area Rapist case while he was in the department as a detective and supervisor. He said that years after the crimes stopped in 1986, the department would get regular plausible tips about a suspect that investigators checked out with surveillance and obtaining DNA from trash.
"Every one of them just seemed so plausible, some of them from retired detectives," said McGinness, now a KFBK radio host.
McGinness said he thought for years that the East Area Rapist had died. Now that a suspect has been found, he said he believes DeAngelo may have thought he was safe from detection and could have kept his "trophies."
"He wanted to relive that experience, and he'd still have that mementos," he said. "I don’t have any of those older papers and treasures from a younger life. But a guy like that might possibly have all that.
"Just my hunch, this guy would save it. He'd save it."
Barbara Harvey contributed to this report.