Caissie — who is now 43 and charged with second-degree murder in the death of 17-year-old Serena Vermeersch in Surrey, B.C., last week — was just 18 when Shayne MacKinnon took him into custody in 1989.
"He exited an eastbound Greyhound bus and followed a young lady home to her apartment. He attacked her with a knife, as I recall, when she unlocked her apartment door," MacKinnon told CBC News.
"I just thought this is the kind of behaviour that could come back in years to come and, unfortunately, it was a self-fulfilling prophecy."
Caissie was sentenced to two years in prison for that attack.
After he was released, he attacked a woman in Abbotsford, B.C., kidnapped her and sexually assaulted her.
Caissie went back to prison, this time with a sentence of 22 years.
Parole hearings began in 2006
In 2006, when Caissie was first up for parole, the board said if he was released he would likely kill or seriously harm someone.
The documents also said Caissie had spent most of his life since the age of 15 within an institution and that he lacked the skills to manage his risk in the community.- MORE | Parole board had considered ex-con Raymond Caissie likely to kill
The following year, the board said Caissie hadn't engaged in any programs aimed at addressing that risk that he might attack someone again.
It also said that Caissie agreed with psychologists that he lacked the ability to live "pro-socially," that he wanted to live away from people, and that he had no community support or employment skills.
In 2013, after a slew of other parole denials, the board said Caissie had been placed in segregation after plotting to attack a prison staff member with a weapon.
Caissie denied it, but only two months before his sentence expired, the board concluded Caissie was still at a moderate-to-high risk to re-offend violently and sexually.
Caissie was released from prison in June 2013 after serving more than 20 years for the violent sexual assault and unlawful confinement of a 21-year-old Abbotsford museum worker in 1991.
At the time of his release, Surrey RCMP issued a statement warning the public of a "high-risk sexual offender" living in the community.
Now, just over a year since his release, Caissie is in custody, charged with the murder of 17-year old Serena Vermeersch.
B.C. Premier Christy Clark said Wednesday that someone like Cassie should be kept behind bars indefinitely in order to keep members of the public safe.
"There is no amount of monitoring that is as good as keeping someone behind bars," she told CBC News.- MORE | Ex-con accused in teen's murder 'could have been kept in jail,' B.C. premier says
Wally Oppal, a former B.C. attorney general says that in a free society it's not that easy.
"We live in a democracy. We can't be imprisoning people who have already done their time in jail," he told CBC News.
But for the man who arrested Caissie all those years ago, something needs to change.
"My heart goes out to the family of those victims," MacKinnon said. "I don't know how to fix the system, but I certainly think there are folks out there that could."
None of the current charges against Caissie have been proven. He is next scheduled to appear in court on Oct. 2.