Simplify the following text for a Grade 8 native English-speaking person.
Original: Boreanaz 's only starring role in a major theatrical film was in 2001 's slasher horror film , Valentine , alongside Denise Richards and Katherine Heigl .
Simplified: Boreanaz 's only starring role in a major theatrical movie was in 2001 's slasher horror movie , Valentine . This movie also starred Denise Richards and Katherine Heigl .