The Jacksonville Sheriff’s Office confirmed a mass shooting and “multiple fatalities,” as well as “many” people transported away from the scene. Police said just before 3 p.m. that one suspect is dead, but officers were unsure if there’s a second possible shooter.
There was at least one shooter. 
( z1 person :ARG0-of ( z2 shoot ) :quant ( z3 at-least :op 1 ) )