CORONA, Calif. -

Criminal charges were filed today against a Corona high school teacher for alleged sex crimes involving five students.

Summer Michelle Hansen, 31, of Corona, is charged with 16 felony counts, including unlawful sexual intercourse with a minor, unlawful oral copulation with a minor and sending harmful matter to a minor. If convicted, she could face up to 13 years in prison, according to the Riverside County District Attorney's Office.

Hansen was a special education teacher at Centennial High School. The alleged crimes involve five underage boys -- all were students at the school, but none were Hansen's students, according to district attorney's spokesman John Hall.

``The crimes are alleged to have taken place from May 2012 through May 2013, and took place in her classroom, in a utility room at the school, in her vehicle while parked near one victim's home, and at another victim's home,'' Hall said.

In mid-June, the Corona Norco Unified School District notified the Corona Police Department about a possible ``inappropriate relationship'' between Hansen and a former student at the high school where Hansen taught.

The school district placed Hansen on administrative leave, and police started an investigation that led to Hansen's arrest on June 20. She posted a $150,000 bond the next day, according to jail records.

Hansen is scheduled to be arraigned on Thursday at the Riverside Hall of Justice.