A registered sex offender pleaded guilty to first-degree criminal sexual conduct Friday for an attack on a St. Catherine’s University student last fall.

Louis Richard Oliver, 47, of Hastings admitted to the crime in Hennepin County District Court. He is expected to receive more than 21 years in prison as part of the plea agreement, according to the County Attorney’s Office. Sentencing is scheduled for May 16.

The victim was walking to a St. Catherine’s building near Riverside Park in Minneapolis on Nov. 19 when Oliver approached her, demanded money and grabbed her by the arm and took her to a wooded area, claiming he had a gun. He took her wallet, backpack and credit cards, then hit her in the face and digitally penetrated her before she was able to escape and run for help. A composite sketch was created of Oliver, who was arrested more than a week later after security officers at Regions Hospital in St. Paul received a complaint Nov. 27 that a suspicious man was approaching women in the parking ramp and asking them for jumper cables for his car. A Ramsey County deputy assisting hospital security recognized Oliver as the man in a sketch released by Minneapolis police in connection with the sexual assault, according to charges. Oliver is a Level II sex offender. Level III is legally considered the most likely to reoffend. Oliver has one sex-related conviction in Minneapolis from the 1990s and another in Black Hawk County, Iowa.

The attack shook students at the school for women. Dozens of community impact statements were submitted to Judge Tamara Garcia for sentencing.