The huge drum magazine that carried 40 EXTRA bullets on gun that killed NYC cop was banned in US until 2004 after Stockton School massacre - but is now legal in 41 states
The magazine Lashawn McNeil, 47, used allowed his gun to carry 40 extra bullets to the Glock's usual 10 when he fatally shot Jason Rivera, 22 and injured Wilbert Mora, 27.
