Vancouver had a third serial killer and police investigating the case of Vancouver's missing women pursued him to his death, an RCMP inspector told the Missing Women Inquiry.

Retired Insp. Don Adam said officers probing the case of the missing women took a second look at other unsolved prostitute murders – and that led them to a suspiciously connected group of killings from the late 1980s, known as the Alley Murders.

The murders were unsolved – but a decade later, police were able to use DNA evidence to get new clues.

"We pulled suspects and what happened in December is the lab developed them and made a match that we had a new serial killer," Adam told the inquiry.

The Alley Murderer's M.O was different than Robert Pickton, who seemed to make women simply disappear. In reality, Pickton was butchering them on his Port Coquitlam farm and dumping the remains at a local rendering plant. Pickton was charged with 27 murders and convicted of six.

It was also distinct from a group of murder cases known as the Valley Murders – three women whose bodies had been dumped up logging roads in the Fraser Valley. Those cases remain unsolved.

Adam says he knows who the Alley Murderer is – but he refused to answer questions from CTV News about the man's identity. RCMP also said they would not identify the man because he never faced a charge.

However on the stand Adam said it's certain that suspect won't ever face justice.

"The DNA was not enough to bring us a charge," Adam said. "We pursued him with every technique police have. When he died one of our people was there with him and he was trying for a dying declaration and he wouldn't give it."

One of the people murdered in Vancouver alleys at that time was Rose Minni Peters. She was described as a shy woman who left her home in Port Alberni after her boyfriend died, said her brother, Gordon Peters.

"My sister was a very unique person. She was the one that I really looked up to. I loved her very much," Peters said.

Peters said he visited his sister a few times in Vancouver but then she disappeared.

"I was devastated. I was crushed. I was very close with her," he said.

He said he's glad that police had their eye on a suspect and he wants to know more.

"I'd like to find out who he is so my brother and sister and myself can move on and say it's over and done with now," he said. "We'd like to find out who it is."

Adam told the Missing Women Inquiry that one thing that stopped investigators from catching Pickton earlier was that there were too many suspects willing to hurt Vancouver prostitutes.

"This file is full of hideous human beings," Adam said. "They needed to be looked at."