VANCOUVER - A former detective has told the Robert Pickton inquiry that the Vancouver police department's repeated denials about a serial killer on the loose is a "common mistake" made by law enforcement agencies.

Kim Rossmo was a geographic profiler with the force and has been credited for being among the first to warn that a serial killer was at work, even though his superiors didn't believe him.

Rossmo drafted a news release announcing that a working group was investigating whether a serial killer was responsible for the disappearance of sex workers from Vancouver's Downtown Eastside.

But Rossmo's superior, Insp. Fred Biddlecombe, stopped the release and disbanded the working group, saying the news release was inaccurate and inflammatory.

Rossmo says he drafted the news release to inform the public and warn them about the possibility of a serial killer.

He also says police agencies often make the mistake of initially denying the possibility of a serial killer and that those denials result in public anger and other problems he hoped to avoid.