FORT LAUDERDALE, Fla. (AP) _ A fourth teenager has been arrested in the beating of a homeless man in a park last month, authorities said.

The 17-year-old Fort Lauderdale resident was charged with aggravated battery with a deadly weapon, police said Thursday.

Three 15-year-old Fort Lauderdale residents previously were charged in the Sept. 20 attack on William Teeters, 44, who was left bleeding and bruised, police said. Teeters was later treated at a hospital.

Authorities identified the three teens from a surveillance video that put them within a quarter-mile of the park 10 minutes before the attack, police said. Authorities had said the boys were considered ``persons of interest'' because they matched Teeters' description of his attackers.

A further investigation revealed that the 17-year-old took part in the beating, said police Detective Katherine Collins.

Teeters was attacked near the site where another homeless man, Norris Gaynor, 45, was beaten to death by a group of teens in January.