I'll get this off my chest - the first 30 minutes of The Prowler are basically slasher heaven. I really mean that. The atmosphere is there, the characters aren't that bad, the killer is imposing, the kills are brutal and nasty...but then...(sigh) things just fall apart and don't get semi-exciting again until the last 10 minutes.
The Prowler might be so wonderful in its first act, because it starts off like most slasher flicks end. By the time its first act has wrapped up, it seems as if already a half-dozen people have been offed and our Final Girl to be has already had a fairly exciting chase sequence.
Sounds great, right? It is. But then she's saved and the rest of the film is spent with her and a policeman doing Scooby Doo-esque detective work in old houses with flashlights with brief interludes of death scenes during a graduation party. It just stops everything in its tracks.
This is not to say that The Prowler is a bad movie. Far from it. It just needed something more exciting and urgent in it's middle section to keep the audience interesting. One never feels like the two leads are in any danger and that drag it down. Still, the special effects steal the show and are wonderful.