Astonishing police bodycam footage shows cops racing into a university building in Prague to search for a gunman who had killed 14 people and treating wounded victims before they found the killer dead on the roof.

The tense footage shows elite cops racing one by one into the Charles University's philosophy building after they were told gunman David Kozak, 24, was shooting at his victims from the balcony with his powerful ZEV-30 rifle on the fourth floor.

The brave officers, armed with rifles and wearing body armour, are seen sprinting up the stairs and raising their weapons - knowing that any minute they could face the gunman. 

The nerve-wracking footage shows the elite cops scouring the corridors for the gunman and for a few seconds, they couldn't locate the door leading up to the fourth-floor balcony from which Kozak was shooting at his victims.

But finally the officers, their hearts racing, barged through a door to the balcony and footage shows Kozak's body lying on the floor next to a pool of blood. 

Police said Kozak, knowing he was surrounded by cops, had killed himself with shotgun after throwing his long-range rifle off the balcony. They said: 'As we were getting close to him on the balcony, Kozak killed himself.'

He had murdered 14 people and wounded 25 more - ten seriously - in the Czech Republic's deadliest mass shooting in history.

Harrowing video shows other police officers discovering injured students inside a classroom and desperately trying to stem their blood loss before evacuating them from the building.