Three north suburban men face charges of pointing a laser beam at a Chicago Police helicopter Saturday night, police said today.

Arrested were Alvin Kang, 25, of Northbrook, Jeremy A. Smith, 24, of Skokie, and Mark P. Lawrence, 25, of Winnetka. The three face misdemeanor charges of unlawful use of a weapon -- pointing a laser at a police officer, according to a release from Chicago Police News Affairs.

Kang, whose defense attorney identified him as a graduate student at Northwestern University and who has a pending misdemeanor battery charge from a fight with a man early June 4, was ordered held in lieu of $10,000 bail in a hearing this morning at Cook County Central Bond Court. Smith and Lawrence have been released on their own recognizance.

A Chicago Police helicopter was above the 400 block of West Menomonee Street in the Old Town Triangle neighborhood on the North Side about 9:50 p.m. Saturday when a beam of light shone into the cockpit. The pilots had a green laser shone in their faces, according to a police report.

The flight crew, which included Chicago police and Cook County Sheriff's personnel, were able to use night vision glasses to pinpoint where the laser was coming from and sent Near North District officers to the location, according to police.

When the Near North officers got to the Menomonee Street address, they found Kang, Smith and Lawrence on a building roof and arrested them, according to police. Kang was seen dropping an object from the roof, according to a police report.

About 2 a.m. on June 4, Kang was arrested in an alley in the 300 block of West Chicago Avenue after a 27-year-old man accused Kang of hitting him in the face when he tried to stop Kang from having a fight with a woman, according to a police report.

Officers responded to a call of two people fighting in the alley to find the 27-year-old walking out of an alley with blood on his face. The man told the officers he was hit by another man after he tried to intervene in a dispute between the other man and a woman.

When the victim asked the woman if she was all right, the man later identified as Kang punched him in the face, the victim told police. When police came on-scene, Kang hid in a dumpster, the victim told the officers. The officers found Kang in the dumpster and arrested him, according to the report.

The victim was not seriously injured and took a taxi to a hospital, according to the report.

Kang, Smith and Lawrence were scheduled to appear in Cook County Court Branch 29 at 2452 W. Belmont Ave. on Aug. 1. Kang was scheduled to appear on his battery charge in the same courtroom on July 8.

Tribune reporter Andy Grimm contributed.

lford@tribune.com