Playing a righteous Brooklyn cop named Gino (complete with working-class Italian-American accent), Steven Seagal wanders into a bar, gazes glumly at all the lowlifes, and then just like Eddie Murphy in 48 HRS. spends an entire 10-minute scene smashing one guy's face after another. The whole movie is like that: Out for Justice isn't so much a thriller as a series of spontaneous muggings, with Seagal exchanging his usual martial-arts moves for a blow-you-away Magnum. What's numbing about this sub-Eastwood potboiler isn't just the grisliness of the violence but the absence of any possibility that Seagal will stumble, or show doubt or pain, or have to challenge himself in order to defeat his enemies. He's proudly invincible, like a school-yard bully who terrorizes kids four grades below him and then walks around the playground saying, ''Hey, am I the guy or what!?''