Uvalde shooting video shows gunman enter shooting, NEW VIDEO

Footage of the Uvalde police response to the shooting was leaked on Tuesday
It shows how Salvador Ramos, 18, sauntered through the halls at Robb Elementary School carrying an AR-15 as a teacher called for help
He then walked into two classrooms and fired for two and a half minutes, shooting off 100 rounds
The new video shows Sheriff's Deputy Felix Rubio in the hallway, in tears being held back by fellow officers, feet away from where his 10-year-old daughter Lexi was shot dead
The first officers arrived three minutes later, but stood back, with one seen checking his cellphone
Nothing happens until Border Patrol agents ran to the classrooms and began firing at Ramos, killing him
Two teachers and 19 children were killed in the May 24 massacre