A renowned criminologist says his warnings a serial killer might be behind the disappearance of sex workers from Vancouver's Downtown Eastside were dismissed as inaccurate and inflammatory.

Kim Rossmo, a geographic profiler who was a member of the Vancouver Police Department at the time, told the Pickton inquiry Tuesday that he tried to set up a working group to investigate the disappearances in 1998 but the group was shut down a month later.

Rossmo, who is credited as being among the first officers to warn about the possibility of a serial killer, testified his concerns were dismissed by Insp. Fred Biddlecombe, who was the head of the major crimes unit at the time.

He said there were several people in the department interested in investigating further, but there was little support at the top.

"No police agency wants to have a serial murder case," Rossmo testified.

"It creates a lot of problems. It creates political pressure, it generates media interest, it might raise levels of community fear, it requires them to respond with a suitable level of resources."

Rossmo said he and another officer were preparing to issue a news release warning the public a serial killer could be at work in the Downtown Eastside. It would have marked the first time Vancouver police had publicly acknowledged the possibility of a serial killer.

But just two weeks before the news release was scheduled to be issued, it was scrapped by Biddlecombe.

Rossmo said the issue came to a head in September 1998 when Biddlecombe threw a temper tantrum during a meeting and dismissed his concerns as inaccurate and inflammatory.

Rossmo also told the inquiry sex workers are particularly vulnerable.

"A street prostitute is the perfect victim that way," he said. "The social response, the police response, the media response is going to be much lower than if you were targeting, say, children or middle class individuals."

Rossmo is expected to continue his testimony for several days.

In a brief address prior to the opening of the inquiry Tuesday, commissioner Wally Oppal compared the Pickton investigation to other serial killer cases including Clifford Olson, Ted Bundy and Gary Ridgway, known as Green River Killer.

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Even though the cases spawned their own investigations and inquiries, Oppal said the same problems keep cropping up — issues of leadership, morale and resources within the policing community.

Oppal said he has to ask himself what he can do differently if previous reports failed to affect change.

Oppal said his final report will examine the systemic failures in the policing environment, including the relationship between police and the victims, and the failures in the organization itself.

Pickton wasn't arrested until February 2002, five years after his name first surfaced as a suspect in the disappearance of sex workers in Vancouver's Downtown Eastside, when officers showed up at his Port Coquitlam farm with a search warrant related to illegal firearms and stumbled upon the belongings and remains of missing women.

Pickton was convicted in 2007 of six counts of second-degree murder, but the remains or DNA of 33 women were found on his farm. He claimed to have killed a total of 49 women. He is currently serving a life sentence.

Rossmo, now a professor at Texas State University, invented a technique of tracking crimes that is used around the world. He was the first Canadian police officer to get a PhD in criminology.

The missing women inquiry, headed by Oppal, is examining why Vancouver police and the RCMP failed to catch Pickton in the late 1990s and early 2000s, and why prosecutors declined to pursue an attempted murder charge against him after an attack on a sex worker in 1997.

A final report is due by June 30, 2012.