I kind of think they just wanted him to know they know..... someone that they looked into earlier and tentatively cleared has now been put back in the line of sight because the car that was parked was a car that he drives and would not have fit in with the Alibi story. Because they didnt ask for people to identify a driver of a certain car. They just wanted everyone (him) to know they know that car was there. Oh! Also. Didnt they say 12_5? I thought about that while I was sleeping. So he was there before they got there.