It takes too long for the victim to turn on the aggressor in ''Pacific Heights,'' and consequently the film, one that could have been most satisfactory, is only partly so.
Melanie Griffith and Matthew Modine are the young couple who buy a house in San Francisco for some $700,000. They can't afford it, but they think they'll be able to make the monthly payments if they rent out two apartments.
A nice Asian couple moves into one. A psychopath moves into the other. Played by Michael Keaton, he is seemingly nice, but any fool could see through him. In defense of the landlords, they do see through him, but the guy is just a little too crafty for them. He simply moves in before they ask him to, before they manage a credit check, before they get the promised money.
Once in, the intruder begins his campaign to harass these people and affect some kind of settlement through lawsuit. He has a history of this sort of thing, but because he uses an alias, it is difficult to trace.
That you can accept. It is the behavior of the police, the judges and the attorneys that gets to you. It is exasperating. Their collective deportment does not make you want to pick up and move to San Francisco.
The new tenant has not paid a dollar in rent, but the law is on his side, and this sort of madness continues through too much of the film. Finally, the girl does a little detecting on her own, and this is when ''Pacific Heights'' improves.
Of course, the ending is ''Friday the 13th,'' and while we are spared the final grab at the ankles by the villain, we are not spared the darting cat and the pigeons that fly into the face of the girl.
The principals do well, Keaton in particular. It is the scriptwriters who are at fault here.
''Pacific Heights'' opens here today. It was directed by John Schlesinger, who does a walk-on in the movie. See if you can spot him.
** A young couple, owners of a new home, are menaced by an unwanted tenant.
CAST: Michael Keaton, Melanie Griffith, Matthew Modine
DIRECTOR: John Schlesinger
RATING: R (sex, nudity, language, violence)
RUNNING TIME: 95 minutes