TACOMA, Wash. -- Pierce County prosecutors say a former elementary school teacher already charged in the kidnapping and rape of a 10-year-old student, also raped a teenager.

Jennifer Rice, 31, has been charged with kidnapping, eight counts of child rape, and four counts of child molestation.

In the first set of charges filed after her arrest in August, prosecutors said Rice repeatedly raped a 10-year-old boy who was a student at McKinley Elementary School where she was working as a contract teacher.

On August 11, Rice allegedly picked the boy up at his home and drove him to a rest stop near Enumclaw and raped him before driving him back to his uncle's house.

Court documents indicate that the two had intercourse several times on previous occasions, including once in the boy's home.

On Monday, prosecutors filed additional charges alleging that in July, Rice raped another boy who was listed in charging documents as being 14 to 16 years old.

Tacoma Police spokesman Mark Fulghum said the teen was not Rice's student, but he would not elaborate on how the two knew each other.

He said their investigation into the rape of the 10-year-old boy led detectives to the second alleged victim.

Rice has pleaded not guilty to all of the charges.

According to the Tacoma School District, Rice taught at McKinley from October 2006 to April 20, 2007. At that time she was placed on administrative leave while the district conducted an investigation to determine whether she was socializing with her students after school.

She is being held in the Pierce County Jail in lieu of $500,000 bail.