PRESCOTT VALLEY, Ariz. (AP) -- Four students at a northern Arizona high school are facing charges after an apparent senior prank. Prescott Valley police say the four 18-year-old males have been issued criminal citations for misdemeanor charges of criminal damage and trespassing. Police say the four also face discipline from Bradshaw Mountain High School. School staff on Monday morning found that a number of planks and more than 150 connective pieces had been removed from several stairway landings. They say the parts were scattered around campus, making it difficult to put back together to make it safe for students and staff. School officials say offensive words were written on windows, doors and walls around campus and some appeared directed at specific teachers. Police say security cameras around campus allegedly were disabled by the four students.