Complex sentence: It is believed that the situation escalated when Knott threatened to report Peyer for unprofessional behavior, and that he killed her by bludgeoning her with his flashlight and then strangling her with rope and then he threw her body off an abandoned bridge into the brush below.
Split into simpler sentences: It is believed that the situation escalated to physicality when Knott threatened to report Peyer for unprofessional behavior. He then threw her body off an abandoned bridge into the brush below.