A women's studies professor is criticizing police for not warning women in Edmonton about a man who allegedly sexually assaulted four women within a week after luring them on a social networking site.

'It's quite possible had they alerted women that some of these assaults could have been prevented.'—Lise Gotell, women's studies professor

"The police could have warned women using social networking sites or dating sites to be specifically careful of someone doing this particular thing," Lise Gotell from the University of Alberta said Tuesday.

"And it's quite possible had they alerted women that some of these assaults could have been prevented."

Edmonton police first announced Tuesday afternoon that they had arrested a 22-year-old man in relation to four assaults that allegedly took place in the Millwoods area of the city.

The suspect has been charged with two counts of sexual assault, two counts of sexual assault with a weapon, three counts of possession of an offensive weapon dangerous to the public, two counts of unlawful confinement and one count each of robbery and theft over $5,000.

Police allege the man contacted the women through a social networking site, developed a relationship with them over several days, lured them to a remote location, threatened and sexually assaulted them.

"The Edmonton Police Service seems to be erring too far on the side of protecting the investigation at the expense and safety and human rights of women," Gotell said.

On Tuesday, Staff Sgt. Brian Readman defended the force's decision not to warn the public, when asked about it by a reporter.

"Not all of the occurrences were reported in the same manner originally and that only after clarifying certain facts with complainants did all the pieces fit together too that we could say, yeah these are all related."

Police weren't able to make that link until the weekend, he said. If they hadn't arrested the suspect on Tuesday they would have likely issued a warning, Readman added.

There are sexual assault cases each year in Edmonton and police don't issue public warnings after each one, he said.

Last summer, police also faced criticism from Gotell, who has published half a dozen academic papers on sexual assault, for not giving women enough information about a suspect they believe may have been responsible for a number of sexual assaults in the Garneau and Aspen Gardens neighbourhoods of the city.

No one has been charged in those cases.