SWAT team gunfire was heard on three Manteca high school campuses Tuesday.It was part of serious training of the Manteca Police SWAT team skills if they should have to take down potential live shooters and protect students and teachers.Various scenarios were played out first at East Union High School beginning at 8 a.m. Officers moved on to Sierra at 9:30 and then to Manteca High at 1 p.m. Participants used blank cartridges for a real life effect.Three teams of four officers spread out over the campuses responding to reports of shots being fired. High school students who are part of the Manteca Police Explorers handled the roles of both shooters and classmates. There were no classes in session on Tuesday.A group of some 20 teachers were on campus at Sierra to watch the drama unfold.