An alleged serial rapist who was in a jail facility already, tried to commit a rape while waiting to be transferred to another facility.

Justin Avery was being detained for allegedly assaulting several women near the Tempe campus of Arizona State University, KNXV reports.

However, he was caught on video at the Intake Transfer and Release Facility, crawling around on the floor to avoid being seen by guards, slithering his way over to a woman who was sleeping. He reached her and was caught taking his pants down.

“We’re appalled by inmate Avery’s actions at our [Intake Transfer and Release] facility,” the Maricopa County sheriff’s office said in a statement emailed to Law&Crime. “This was a unique incident and the first of its kind in four years, since the ITR facility was open.”

According to investigators, Avery admitted that he was drawn to the woman and wanted to “rape” her, KNXV reports.