BARTOW, Fla. -- Criminal charges were dropped Friday against three of the eight teenagers involved with the notorious videotaped beating of a central Florida teen, prosecutors said.

Kidnapping and battery charges were dropped against Cara Murphy, 16, Stephen Schumaker, 18 and Zachary Ashley, 17, said Chip Thullbery, a spokesman for the state attorney's office in Polk County.

"After further investigation, there was insufficient evidence for prosecutors to move forward," Thullbery said.

The five other teens involved remain charged.

Two of the eight girls confronted Victoria Lindsay on March 30 when the 16-year-old walked into the home, yelling and threatening her, according to the arrest report. Another girl struck her in the head several times and then slammed her head into the bedroom wall, knocking her unconscious.

When Lindsay woke up, she was on the couch in the living room surrounded by the six girls, according to the report. The teens blocked the door, held her down and began beating her.

Lindsay was taken to the hospital by ambulance and treated for a concussion, damage to her left eye and left ear, and numerous bruises, according to the report.

Lindsay's father had said the motivation for the attack was to produce a video that would become popular on the video-sharing Web site YouTube. But the mother of one of the teens said that Lindsay had provoked them by threatening and insulting them on MySpace, a social networking Web site.