the first shooting was aimed at the national museum of the marine corps in triangle, virginia on october 16, 2010. some bullets from a high-velocity rifle went through the atrium skylight. the second shooting happened on october 19, 2010 shortly before 5 a.m. someone shot at the south side of the pentagon in arlington, virginia. the bullets broke windows on the third and fourth floors. special glass stopped the bullets from entering the building. the offices behind those windows were empty because of repairs. the pentagon reservation was temporarily closed because the police searched the area for evidence. the building was reopened about 5:40 a.m. the joint terrorism task force is leading the investigation into the incident. in the third shooting, the same rifle shot the marine corps museum again on october 29. the same rifle was used to attack a marine corps recruiting center in chantilly, virginia on october 26.