Montgomery County police have charged three students at Col. Zadok Magruder High School in connection with the June 1 sexual assault of another Magruder student, a 15-year-old girl, in a wooded area near the school.

A 16-year-old boy from Derwood was charged Monday night with second-degree sex offense, attempted third-degree sex offense, theft and other charges. A 15-year-old Rockville boy was charged with attempted third-degree sex offense, second-degree assault, misdemeanor theft and reckless endangerment, and a 16-year-old Gaithersburg boy was charged with second-degree assault.

The Washington Post generally does not publish the names of juveniles charged with crimes or victims of sexual assault.

The victim, a Rockville girl, told police that she voluntarily left the Rockville school with the three boys after the first period June 1 to "hang out" in a school parking lot and that the group remained there until the end of third period, according to a source close to the case who spoke on condition of anonymity because the case is pending.

The girl voluntarily performed sex acts on two of the boys, the source said. The group then went into the wooded area, ran into a group of four other people and smoked marijuana, the source said.

According to the source, after the girl said she felt tired and appeared to lose consciousness, one of the boys stole two CDs from her backpack and another took $5.

One of the boys groped the girl and attempted to get her to perform a sex act on him, but the girl was in and out of consciousness, the source said. The 16-year-old Derwood boy drew an obscene picture on the girl's stomach with a marker, the source said.

About 2:30 p.m., police arrived at the wooded area to find the victim fading in and out of consciousness, police said. The girl was taken to the hospital, where she was treated for minor injuries and released the same day, said police spokeswoman Lucille Baur.

The 16-year-old Derwood boy appeared yesterday in Montgomery County juvenile court in shackles and handcuffs. Montgomery Circuit Court Judge David A. Boynton ordered him to be fitted with an electronic monitor and said the boy cannot leave his home pending further court proceedings. The other two boys are in the custody of their parents pending further court action.