Former NFL DB Tony Beckham -- a Titans 4th-round pick in 2002 -- beat the hell out of a man after he allegedly caught the guy masturbating outside his 15-year-old daughter's window.
Cops in Palm Beach County, Florida say Tony saw a man with his hands down his pants in the bushes next to his daughter's window Monday morning ... and went after him when he saw the guy making masturbating motions.
Police say Tony chased the guy down about 50 feet from his house ... and proceeded to smash the guy up bad -- breaking his face in a couple different places.
Cops arrested the man -- a 48-year-old named Geoffrey Cassidy (who claimed he was a transient) -- and booked him for Lewd or Lascivious Exhibition in the Presence of a Child.
If convicted on that count, Cassidy faces up to 15 years in prison.
Cassidy is still being held in Palm Beach County Jail on $1,500 bond.
Beckham played 5 seasons in the NFL from 2002 to 2007 ... logging 6 total starts and 1 career interception.