LAKEWOOD, Colo. -- A man who has been accused of videotaping women while he raped and groped them has been charged with 19 counts of sexual assault, but police don't think their case is complete.

According to court records, police believe 32-year-old Timothy Layne Martinez sexually assaulted two women while they were asleep or in some "altered state" -- possibly from drugs or alcohol.

The sexual assaults allegedly occurred in Martinez's Lakewood home between February and November 2006, but police didn't begin investigating until a victim came forward earlier this year, Jefferson county prosecutors said.

Martinez was arrested and charged earlier this year as result of that investigation.

However, police aren't done.

Investigators want to interview a woman seen on a black and white video but they don't know who she is. They released three photos of the woman, who appears to be blond and in her late teens or early 20s.

Authorities aren't saying why they want to talk to her other than to say she "may have information about this case."

Anyone who knows her or who may have information about her is asked to call Lakewood police investigator Karen Turnbull at 303-987-7217.

The two alleged victims knew Martinez, but prosecutors are not disclosing the nature of their relationship.