Florida shooter's riffle reportedly jammed during the shooting and he had 180 rounds left

Authorities believe the Florida high-school shooter's weapon jammed when he was changing magazine clips during the massacre, likely prompting him to flee the scene before he finished his killing spree, CBS Miami reported on Tuesday.

Nikolas Cruz, 19, allegedly killed 17 people at the Marjory Stoneman Douglas High School on February 14, firing nearly 150 shots in just seven minutes.

Investigators believe Cruz had tried to gun down down fleeing students from a makeshift sniper's nest on the third floor of the building, but that hurricane-proof glass in the stairwell window stopped his bullets.

A law enforcement source told CNN that Cruz still had roughly 180 rounds of ammunition left when he grew frustrated with the reload attempt and fled.

Authorities said Cruz then ditched his weapon and escaped by blending into a crowd of students.