A Vancouver DJ and former political campaigner has been arrested and charged in four violent sexual assaults against girls as young as six over a 15-year period.

Ibata Noric Hexamer, 42, was arrested on Friday and now faces 23 charges including sexual assault with a weapon, unlawful confinement and robbery.

The former administrator with the municipal COPE party was identified as a suspect after investigations into three connected cases in which girls were raped at knifepoint.

"The monster who committed these crimes left DNA evidence behind at all three scenes," Chief Const. Jim Chu told reporters at a press conference Monday.

"The chances that the DNA doesn't belong to him are one in a quadrillion."

In the most recent case, a Surrey six-year-old was walking along 62 Avenue with her 12-year-old brother and a 15-year-old male friend in July 2009 when they were approached by a man asking for directions.

The little girl was grabbed by the man, who produced a knife. He then led her into a wooded area, forcing the two older boys to follow and kneel nearby while he sexually assaulted the girl.

"The family of the victim has moved away from the area due to the emotional trauma of this incident," Chu said.

Police believe Hexamer was responsible for assaulting two 14-year-old girls at knifepoint in a wooded area of Delta two years earlier.

Investigators have also connected Hexamer with the sexual assault of a 13-year-old girl near Vancouver's Lord Nelson Elementary in 1995. They believe that he told her he had a knife, pulled her into an outdoor stairwell and held his hand over her mouth while he raped her.

"The victim is now 28 years old and she has been waiting all this time for justice," Chu said.

Hexamer remains in police custody. Investigators say that he has had previous contact with police, but has no criminal record.

‘This guy is scum'

The three incidents were linked after the Surrey assault last year, when police matched DNA from all three crime scenes and asked for help identifying a suspect from composite sketches.

At the time, the father of the six-year-old victim pleaded for anyone with information about the attacks to call police.

"This guy is scum. Don't feel bad about phoning tips or phoning me," he told CTV News.

He also had a message for the suspect: "Turn yourself in before I catch you. Turn yourself in so my daughter can sleep at night."

‘A mild-mannered kind of guy'

A friend who has known Hexamer for more than 10 years was shocked to hear of his arrest.

"It's totally out of character," the friend told ctvbc.ca. "I never thought of him being like that."

The friend, who asked to remain anonymous, said that Hexamer is a quiet man who has never shown violent tendencies.

"He's a mild-mannered kind of guy."

According to an alumni biography at the University of British Columbia, Hexamer graduated from the school with a bachelor's degree in theatre design and technology in 2002.

Since then, he's worked with the COPE party as an administrator and a personal assistant to current city councillors Ellen Woodsworth and Tim Stevenson, as well as former representatives Fred Bass and Tim Louis.

Louis, a Vancouver lawyer who uses a wheelchair, said that he hired Hexamer to help him with personal tasks in the evenings. He was surprised to hear of the allegations against his former assistant, and told ctvbc.ca he had "not one iota" of suspicion about Hexamer.

"I'm very, very angry towards whoever the perpetrator is, and if it's him, I'm very, very angry toward him," Louis said.

Alvin Singh, the executive director of COPE, told ctvbc.ca that Hexamer worked for the party before the 2005 and 2008 civic elections.

"He had two minor involvements with COPE in relatively low-level positions," Singh said, adding that they were "purely administrative roles."

Singh described Hexamer's work with individual COPE councillors in 2002 as personal arrangements with those politicians "bordering on volunteer duties."

Singh declined to comment on the allegations against Hexamer, except to say that "they're obviously serious charges and that's about all I can say."

Hexamer also worked for the federal NDP as a database manager during the 2006 election.