‘One Good Cop’ (R)

"One Good Cop" bends over backwards to tell you what a mensch Michael Keaton is. He talks Uzi-toting wackos out of blowing their families away. He busts heads only when he has to. He's been married to Rene Russo for eight years. ("I wouldn't know how to cheat," he confesses.) He even spares her the gory details of his bruising day.

"Got rear-ended by a gypsy cab," he tells her, nobly turning away his black-eye.

Can I just say it? Put it there, Mikey. Those superguy qualities are about to be tested. When a colleague is killed in action, Keaton finds himself legal guardian of his friend's three preteen daughters. What's an excellent guy to do? He and Russo take on pint-size angels Grace Johnston, Rhea Silver-Smith and Blair Swanson. They put them to bed. They soothe them from nightmares. They even administer insulin injections to the diabetic one.

"I told Dr. Gelb I could give myself the medicine," cheeps the little trouper. "But he says I'm still too young."

How's your gagging reflex so far? If it hasn't completely blocked your air passages, you might go for this. But chances are you won't take to the cops 'n' crackheads action. We're talking big guns and bloody bodies. The movie flips from gritty to dippy, then back again. Perhaps writer/director Heywood Gould thought he was adroitly changing pace. All he did was make two different movies, a New York cop flick and "Mr. Mom."

Actually, the total is more like six movies. Other elements are thrown in, as if scriptdoctors were hired by the dozen. If there's one thing to be said about "Cops," it's that you never know what movie you're in. In one scene, Keaton and partner Anthony LaPaglia have to negotiate with crack-deranged gunman David Barry-Gray. They cool him out so easily, you'd swear you were watching a police crisis-control instructional video.

There's a healthy dose of Just Say No messages about crack. You'll see how the well-meaning social system can break apart a happy family. The movie also laments a world of increasing crime and dwindling police resources: "This is the third time I got robbed this month," barks a citizen. "What are you going to do about it?"

There's a subplot in which priest Vondie Curtis-Hall needs money for his shelter and orphans. There's a hissy vendetta between Keaton and ruthless Latino drug dealer Tony Plana. It results in a bloody finale and an incredibly goofy plot twist that suggests the title "Ninja Robin Hood." But just about anything goes in this movie anyway.

The ending comes as little surprise, showing even good guys bend the rules sometimes. It's the only way they can finish first.