A 17-year-old was beaten on the Sandy TRAX platform Friday night by three teenagers who sought him out for dating an ex-girlfriend of one of the alleged attackers.

Sandy Police Sgt. Dave Worthington said the attack happened about 7:30 p.m., and that according to witnesses, the three teenagers used brass knuckles on the victim. The three attackers were juveniles.

Two of the three were caught by police nearby and had both run away Thursday from a Kearns juvenile detention center. The third had not been caught as of Friday night.

The victim was treated at the scene and released to his parents.