Officers responded to the Gateway Mall on Saturday around 11 a.m. after receiving a call about a sexual assault.
Police say a woman in her mid-20s was lured into a unisex restroom in the mall where the assault happened.
With the help of mall security, the suspect, 27-year-old Brexin Reed Shulz, of Eugene, was located in the mall shortly after and arrested.
Police say Shulz is a convicted rapist and a registered sex offender.
Shulz was lodged in the Lane County Jail for first degree sodomy and first degree unlawful sexual penetration.