Troubled Mavericks rookie Leon Smith was back in the custody of Chicago police last night, hours after being released on bond from a charge of threatening his ex-girlfriend. Police said they are interviewing the basketball player about a complaint that he broke several windows of a new car belonging to the mother of his ex-girlfriend yesterday afternoon.

Smith, who went to the NBA directly from Chicago's King High School, was arrested Thursday night on a charge of assaulting his ex-girlfriend at a Chicago high school. He posted $100 bail yesterday morning and was released pending a Dec. 23 court appearance.

The ex-girlfriend's mother called police later yesterday, saying Smith went to her home on Chicago's West Side and smashed her car windows. The new accusations are just the latest against the 19-year-old, who spent his childhood as a ward of the state but seemed headed to a better life.

A star high school player, he averaged 25.5 points and 14.5 rebounds as a senior. Then he made a big leap, going right to the NBA as a first-round draft pick. Signing a $1.4 million contract, however, has not done any wonders for him.

Smith has not played a minute in his troubled rookie year with the Mavericks. His arrest follows an apparent suicide attempt last month, and a charge of criminal mischief after he allegedly smashed the window of a friend's sport utility vehicle.