Pinal County Sheriff's Office investigators want to speak with anyone who saw suspicious activity about 11 a.m. Tuesday in the Cambria subdivision in San Tan Valley.
According to Lt. Tamatha Villar, a sheriff's office spokeswoman, a man walked into the unlocked home of a woman and assaulted her.
Villar said in a news release that she could not provide any other details, but Sheriff Paul Babeu said in a statement that it was a "terrible crime."
Villar said the woman was unable to provide a description of the assailant.
Anyone with information should call (520) 866-5112 or (800) 420-8689.