what was the main thing in chapter 10

As Stacy approaches Jarrod, Jeff gets in her way, foreshadowing the concept that he is Jarrod's friend. After Jarrod drives off, Stacy collapses in the grass. The partygoers are shocked Jarrod is the killer, but one girl mentions seeing a gun in his glove compartment during a date. Jeff takes control of the situation, telling the party guests to go back inside because he will make sure Stacy gets home safely. Jeff already called the police, and he assures Stacy that Jarrod will not come to her house.