A Washington County grand jury has indicted a 22-year-old woman on first-degree rape and other sex crimes.

Melissa Chacon of Cornelius pleaded not guilty at her arraignment Thursday on one count of first-degree rape, one count of using a child in a display of sexual conduct and two counts of first-degree sexual abuse, court records say.

In an interview with detectives, Chacon admitted to having sex with a 7-year-old boy, according to a probable cause affidavit. She described various sex acts with the child that occurred multiple times between January and February, the affidavit says.

Melissa Chacon

Hillsboro police arrested her in the case on April 29, records show. She remains in the Washington County Jail on $750,000 bail.

All of the charges against Chacon carry mandatory minimum prison sentences.

-- Emily E. Smith

esmith@oregonian.com

503-294-4032; @emilyesmith