AMES, Iowa (AP) — An Iowa State University graduate student accused of sexually assaulting a woman in April at his apartment has pleaded guilty to assault with intent to commit sexual abuse.

The Des Moines Register reports that 33-year-old Jona Paulus entered the plea Monday. In exchange, the court agreed to sentence Paulus to 90 days in jail with credit for time served. Paulus also must register as a sex offender for the rest of his life.

Police say Paulus held the victim down and sexually assaulted her on April 6. When the woman was able to get up, she began recording Paulus with her phone and can be heard telling him, “I told you no.” Police say he replied, “I know. I know.”

Paulus has also been charged with sexual exploitation of a minor and possession of an image of a minor in a sex act in a separate case.