Four teenage girls assaults "mentally challenged" woman, posts video of attack on Facebook, Pa. police say

(CBS/AP) CHESTER, Pa. - Four teenage girls were held Friday on $50,000 bail for beating a woman sitting on her stoop outside Phildadelphia, Authorities said the attack was recorded on one of the youths' cellphones and posted on Facebook.

Police said the 16- and 17-year-old girls were charged as adults in the attack of a 48-year-old Chester woman they described as "mentally challenged." The girls were charged with aggravated assault, reckless endangerment, burglary and harassment.

Investigators are still searching for two other teens in the Tuesday attack. Authorities said the victim was punched, kicked and hit with a shoe and chair, and that she suffered cuts and bruises but no broken bones. She was said to be at a crisis unit.

"It appears just for fun," Detective James Nolan said. "There hasn't been a discernible explanation as to why."

Police first obtained the footage on Thursday by the Delaware County Daily Times.

The video shows a group of girls walking along before suddenly deciding to attack a woman sitting on her stoop. The teens then followed the victim into her home as she tried to escape, taking turns punching and beating her. They quickly fled.

"I can't comprehend it," said Crystal Pate, who knows two of the girls and also works in the neighborhood where the attack occurred. "Obviously they were showing off. That's not something you do for fun."

Pate said the victim regularly sits on her front stoop and sometimes curses people.