It's a dark part of Hawaii's history that's hardly talked about.
Five females murdered on Oahu in the mid-1980s, and police believe it was the work of a serial killer.
The suspect was never caught, and the case remains open.
Regina Sakamoto was one of the victims. She was only 17 years old when she disappeared in January 1986.
"She was late for school that day," recalled her brother, Omar Sakamoto. "It was in Waipahu. She was sitting at the bus stop in front of Diners in Waipahu."
That was the last time anyone saw Regina Sakamoto alive. She was abducted, raped, strangled, and bound. Her body was found floating off Keehi Lagoon.
Omar Sakamoto was in the fifth grade at the time.
"I used to look up to her. She'd babysit me and stuff like that," he told KHON2. She was "very bookish, smart, fun loving, everybody's friend, that kind of thing."
Regina Sakamoto was the second of five murder victims whose bodies were found with their hands tied behind their backs. All were female between 17 and 36 years old.
The killings prompted the Honolulu Police Department to form a task force that included an FBI profiler who helped put together a profile of the person they believed could be the suspect.
He was described as a Caucasian male in his 30s to 40s with no criminal record. The profiler also suspected the killer targeted women near where he lived or worked.
"He's an individual who may be, at this particular juncture, may be experiencing girlfriend or marital problems and the selection of victims is probably the result of opportunity or chance encounters," former Honolulu Police Chief Douglas Gibb said back in 1986.
Eventually a suspect was arrested, but he was never charged and has since passed away.
Former homicide lieutenant Gary Dias was the head of HPD's homicide detail at the time.
"Based on the evidence we had and the witnesses we had and physical evidence, we felt we had enough," Dias said.
When asked what he would like to see happen at this point, Omar Sakamoto said, "I really would prefer DNA testing, because if the guy is innocent, then he's innocent."
At the time, all police could do was test for blood type.
"DNA could've been a much greater asset for us in that particular case," Dias said, "and it's useless in today's age, because 82 percent of the world are types O and A."
Unfortunately back then, there was no cell phone video, and surveillance video wasn't common.
"Digital evidence is extremely important toward the advancement of investigations," Dias said.
"It's kind of sad that both my parents, you know, they're not here to, even if it does get resolved, they're not here to see it," Omar Sakamoto said. "I just want, what is that, closure."
HPD told KHON2 that homicide detectives are stepping up efforts to review cold cases. That includes looking for untested evidence, and any evidence that should be retested using updated technology.
The department has also created a database with all the information on what's been tested and what needs to be re-tested, which should help current and future investigators.
So what about retesting evidence in the serial killer, Diane Suzuki, and Lisa Au cases?
HPD says it can't comment because those cases are still open, but promised to "pursue all leads, whether it's from someone who has new information or a new form of DNA testing. We are committed to getting justice for victims and their families, no matter how long it takes."Full HPD statement:
"Earlier this year, homicide detectives stepped up their efforts to review unsolved murder cases, looking for untested evidence and any evidence that should be retested using updated DNA technology. HPD also created a database with information that thoroughly documents which items of evidence have been tested and which items should be retested when new technology becomes available. The database will serve as a resource for both current and future investigators.
We can't comment on open cases. However, because there is no statute of limitations for homicide, a case will remain open until a suspect has been identified. We will pursue all leads, whether it's from someone who has new information or a new form of DNA testing. We are committed to getting justice for victims and their families, no matter how long it takes.
DNA technology played a key role in the 2014 prosecution of Gerald Austin, who was convicted of murdering 81-year-old Edith Skinner in her Kalakaua apartment in 1989. Twenty-five years after the victim's death, Austin was sentenced to life in prison without the possibility of parole."