The Police question David and Robert about them leaving the club on that fateful night and they say they took the tram back home at around 12.30 a.m.
Later, when Vanessa steps out from the same club and waits for the Tram, a line worker comes and tells her that she should take the bus instead as the Trams are being renovated and does not run after 10.00 p.m. She asks him since when, to which he replies, about a month.
Being a small town, the Police would have surely known that the Tram service is suspended after 10.00 p.m. and that David and Robert has told a lie about taking the Tram at 12.30 a.m. and would have arrested them subsequently.