Investigators could have linked a convicted child molester to a sexual assault using DNA evidence at least two months before he allegedly went on a rape spree, but a computer glitch prevented it, authorities said.

Brent Brents (search), 35, was arrested Friday on suspicion he sexually assaulted at least five women and girls this month in the Denver area. He is also suspected of raping a woman in October, a federal arrest warrant shows. Formal charges have not been filed.

Dave Fisher, who oversees police investigations for the city, said "bad timing" and computer problems prevented police from arresting Brents earlier.

According to an arrest affidavit, a 25-year-old woman told investigators in October she was attacked by a knife-wielding man and police obtained semen samples at a hospital later that night.

But police said the contractor responsible for handling FBI and the Colorado Bureau of Investigation (search) data left out Brents' DNA sample when it was transferring data to a new computer server on Dec. 14.

Brents' DNA profile is in a state database containing information on 37,000 offenders because he was convicted of raping two children in 1988. Investigators would have been able to identify him had the sample been entered into the contractor's database.

The Denver crime lab compared the samples with the state database and was able to link the rape to Brents — but not until Feb. 16, after the recent attacks, police said

Police said they were told by the contractor it has new quality control measures to prevent the glitch from happening again.