Complex sentence: Tony fails to realise that his investigation has not gone unnoticed, and Petrulio in turn tracks the pair back to the motel where they are staying, only the number of bystanders present preventing him from taking a shot at an unsuspecting Tony and Meadow.
Split into simpler sentences: Tony fails to realise that his investigation has not gone unnoticed, and Petrulio in turn tracks the pair back to the motel where they are staying. However, the number of bystanders present prevents him from taking a shot at an unsuspecting Tony and Meadow.