Within a 3-square-mile area of Milwaukee's north side an unknown man strangled six women police say were prostitutes between 1986 and 2007. But it wasn't until this past week that the city's top cop said recent DNA tests had linked the killings.

Some people in the community, including the women's' families, wonder why it took police so long to discover the DNA link and announce it, and whether some officers' biases against the victims' lifestyles and race kept them from focusing their attention on the crimes.

"Crack whores," is how some officers in past decades referred to prostitutes, said LaVerne McCoy, who retired as a sergeant in January after 25 years in the Milwaukee Police Department.

"They are forgetting that crimes are being committed and this person is continuing to do this because of our attitudes about the victim and that's what our priorities should be: Get this murdering criminal off the street," McCoy said.

Suspicions of a serial killer had swirled for years. A 1997 Milwaukee Journal Sentinel article said then-Chief Arthur Jones assigned officers to investigate strangulations of women on the north side after Joyce Mims was found dead in a vacant house.

Last Monday, Police Chief Ed Flynn said DNA tests in the past couple of weeks had linked her death and at least five others to the same unknown man. He said the same person had sex with a 16-year-old runaway whose throat was slashed, but that someone else likely killed her.

The district attorney, FBI and state agents now are all investigating, but have released little information.

All the victims were black except the teen, who was white. Their ages ranged from 16 to 41.

Police have submitted or resubmitted DNA samples from more than 20 other unsolved homicides to the state's crime lab to see if they are related.

Relatives of at least two victims think racism hampered investigators. And at least one former prostitute and an organization that helps prostitutes think classism played a role.

"We do not feel it would help at this point in the investigation to respond to specific questions on cases or statements that don't help us find whoever has been preying on these women," police spokeswoman Anne E. Schwartz said by e-mail, noting criticism is a normal part of police work.

Flynn had said advances in DNA technology linked the homicides. But Wisconsin started using that advanced technology used to link the cases in 2000 — when it started collecting DNA from all felons for the database.

The state crime lab had been backlogged for many years, but has hired 30 more people since 2007 and started using robotic testing to speed DNA testing.

As for allegations of bias, police union President John Balcerzak worked patrol for about 20 years and said he never saw any officer treat victims differently.

"You react to the situation, you don't let your emotions or personal feelings be involved in it," he said.

The department has a clearance rate of 78 percent for 2,605 homicides since 1986, but only a 31 percent clearance rate for the 42 prostitute homicides during that time.

"Our challenge is to find an unknown suspect who conducts his business in secret with consensual potential victims," Flynn said.

That's not good enough for Darian Mims, 36, the oldest of Joyce Mims' four sons. He suspects racism in the department. He said his mother may have used drugs but was not a prostitute. She was home every night with her children, he said.

"Even when my mom was murdered ... you know how many police or detectives came out to talk to me? None. Not one," said Mims, who lives in Madison.

"They just put things in categories trying to link some (expletive) together," Mims said. "And they are not putting (expletive) together and it's been 12 years," he said.

Shannon Farrior, daughter of 1995 victim Sheila Farrior, also disputes allegations that her 37-year-old mother was a prostitute. She, too, wondered if police were affected by race.

"They just figured there were a lot of black women who got killed and they didn't put a lot of effort into finding the killer," said Farrior, of Chicago.

Former prostitute Michelle Kasper lived the lifestyle for four years — she said she has been drug free for almost a year — and said police didn't take reports of rapes and beatings of prostitutes seriously.

"The odds are against people in addiction that they really don't see anybody pulling out of it," said Kasper, 32. "And it does happen, there are stories every single day. They just write us off."

Deacon Steve Przedpelski of the Franciscan Peacemakers, which helps prostitutes, said most have been sexually abused and are addicted to drugs, making it hard for them to leave the lifestyle behind.

He thinks classism had something to do with the crimes going unsolved.

"I think people should really try to stretch themselves — if they are absolutely so pro-life that these women are creations of God and their lives are important and we should be caring for them as much as preventing a baby from being aborted," he said.

McCoy, who is also former president of an organization of black police officers in Milwaukee, said other reasons why the crimes were unsolved might include overworked officers, officers failing to share information, or the department being "stuck in antiquated procedures."

Now many of the old timers with biases are gone, and the new chief, who started in 2008, likely helped move the case forward, she said.

"He is making people think outside the box and he's making them accountable," she said.

McCoy admitted she, too, was guilty of losing her objectivity about the women.

"(Officers) try to help them over and over again and you just ... get frustrated and you think, 'You get what you get,"' she said. "Even I'm not above that looking down on people because of the bad choices they've made."

"We fail to understand the human part of it: that they are addicted to this drug that has taken over their will, their soul."