BELLEVUE, Neb. (AP) _ A 19-year-old man was lured to a park and stabbed to death by a gang of five people for roughing up a girl during an episode of group sex, authorities said.

Six people, including a married couple and two 16-year-olds, were arrested after Scott D. Catenacci's body was found in the park Wednesday.

Three of those arrested had engaged in group sex with Catenacci about two weeks ago, Sheriff Pat Thomas said. They plotted to kill him because he ``roughed up one of the girls,'' Thomas said.

The sheriff would not specify what Catenacci had done.

Catenacci was lured to the park in this Omaha suburb on the pretext that someone wanted to buy his laptop computer. He was stabbed repeatedly in the upper body and apparently struggled with his killers, Thomas said.

Five of those arrested were at the murder scene and the sixth knew about it and tried to cover it up, the sheriff said.

Catenacci was killed Tuesday night or Wednesday morning. His parents reported him missing after he didn't come home from work at a doughnut shop.

``This thing's kind of bizarre,'' the sheriff said. ``It's more involved than any soap opera.''

Brandy Glynn and James Hargett, both 19, Niccole Wetherell, 18, and two 16-year-olds were arrested on murder charges. Ms. Glynn's husband, 19-year-old Christopher Glynn, was charged with being an accessory to murder.

None of the suspects' families were available by telephone.

Neighbors on the quiet street where Catenacci lived less than a mile from the park where his body was found called the scene Thursday ``heartwrenching.''

``I saw his father hugging his (Scott's grandfather) earlier,'' said Sandra Wagner, 35, who works at a Bellevue grocery store. ``Myself I can't comprehend it all. I mean, the fact that they killed him over sex. I thought they were friends.''