Once on the train (according to what the channel said was a leaked police statement, aired Tuesday night) a police officer pinned de Menezes down when another officer shot him.
de Menezes was held down by a different person than who shot him.
It said one policeman held him down and the other shot him. My statement is definitely correct. 
( z1 hold :ARG0 ( z2 person :ARG1-of ( z3 differ :ARG2 ( z4 person :ARG0-of ( z5 shoot :ARG1 ( z6 person :name ( z7 name :op "de" :op "Menezes" ) ) ) ) ) ) :ARG1 z6 :ARG3 ( z8 down ) )