Raymond Lee Caissie, the ex-convict charged with killing a Surrey, B.C., teenager last week, was considered likely to kill or seriously harm someone, according to documents released by the Parole Board of Canada.

Raymond Lee Caissie, 43, has been charged with second-degree murder charge in the death of Serena Vermeersch, 17, after her body was discovered on Sept. 16 near a set of railroad tracks in Surrey's East Newton neighbourhood.

Caissie's arrest has touched off a fierce debate about why — and under what conditions — he was released from prison in 2013, having never been paroled and after serving a full sentence of 22 years for a violent sexual assault.

Raymond Lee Caissie​, a high-risk sex offender who was released from prison last year after serving 22 years for a violent sexual assault, has been charged with the murder of Surrey, B.C., teen Serena Vermeersch. (RCMP)

B.C. Premier Christy Clark says the case demonstrates a need for more tools to keep an offender deemed high risk in prison.

"I suppose we will never guarantee our society is entirely safe, and we certainly can't keep everybody behind bars, but there are a few cases like this one, and thankfully not many, where we can do a better job," Clark told CBC News this morning.

Former B.C. attorney general Wally Oppal said the case, and the debate it has sparked, presents difficult problems for society.

"You can't in the absence of any kind of compelling evidence, start to take criminal proceedings against a person who has already served his or her sentence. And that's the real dilemma that you have here in a democracy."

A lifetime of violence and prison

According to parole board documents, Caissie is a career criminal was first incarcerated at the age of 15.

He served 22 years for kidnapping and violently and repeatedly raping an Abbotsford, B.C., museum attendant in 1991.

He was denied parole eight times because he was considered a medium to high risk to re-offend right up until the end of his full sentence.

"If you are released you are likely to commit an offence causing the death of or serious harm to another person" the parole board concluded after his first hearing in 2006, noting his numerous convictions for violent crimes and sexual assaults.

Photo of Raymond Lee Caissie released by the Matsqui Police Department after he was charged with the brutal sexual attack on an MSA Museum employee (Matsqui Police Department)

The parole board documents show how, despite completing several treatment programs, including the Intensive treatment for sex offender program, Caissie showed no insights into his violent behaviour.

"You have a long history of sexually inappropriate and violent behaviour dating back to your youth," wrote the board after his 2007 hearing.

He clashed with prison officials over drugs, violence and weapons behind bars.

"In addition to your sexual deviancy, a major risk factor for you is your tendency to ruminate over perceived slights and fantasize about taking revenge," said the 2008 report.

The documents reveal police suspected him of other sexual assaults in the Matsqui Institution. Toward the end of his sentence, Caissie landed in segregation for his role in a violent prison plot to attack a guard.

In a final report in January 2013, a month before his release, the board noted he had no plan for his release, and concluded he was still likely to harm another person if released.

"There has been no change in the risk you present to the community and, in fact ... your serious institutional behaviour over the past year has had a further negative impact on your case."

Three months later Caissie was released to live in Surrey, under the supervision of the Surrey Probation Office and the RCMP, who issued a special warning to the public about his release.

On Monday, he was charged with second-degree murder in the death of Vermeersch.