Prince William school staff and county police are holding a community meeting at 7 tonight at Bull Run Middle School to discuss emergency procedures in the wake of an incident last week in which a student brought three rifles to school.

"We want to continue to maintain the open lines of communication with students and parents that have worked so well in this case," Superintendent Edward L. Kelly said in a statement.

The 12-year-old seventh-grader was arrested Friday without incident. Police have not released his name, and a trial date has been set for July 6, prosecutors said. The boy is charged with possession of a firearm by a minor, use of a firearm in commission of a felony, conspiracy to commit abduction for money and conspiracy to commit murder.

The boy's mother, Naomi Lewis, 38, a cafeteria worker at the school, also was arrested and charged with possession of a weapon on school property. Police said she drove her son to school Friday and saw weapons in her van. She locked the vehicle but did not report that the guns were there. Her son later retrieved them with a key to the van that his mother did not know he had, police said. Police have also said she did not know of the alleged plot.

While the incident was going on, students were "locked down" in their classrooms. Police swept through the building and then released the students, who were picked up by their parents at nearby Tyler Elementary.

School Board member Don Richardson, whose Gainesville District includes both schools, said the meeting should be "a chance for parents to get the straight facts about what went on." He said they can also learn more about Bull Run's emergency plan. Similar plans are in place at schools across the county, and schools do practice drills every year.

"It's also a chance for people to give us some feedback about things that we can do in the future to improve the plan," he said. "Every time we go through an exercise we learn new things, but this is the first time it's ever been tested."