[h=3]Gunman was already at Walmart[/h]
While the rewound footage might not have increased the number of casualties, it did hamper efforts to locate the gunman.
"Somebody would say, 'He's on the second floor,' and we had guys on the second floor saying, 'We're on the second floor, we don't see him.' That's when we figured out there's a tape delay," Pustizzi told the Sun Sentinel.
According to police scanner traffic from the streaming website Broadcastify, at 2:43 p.m. on February 14, police found someone to give them access to the school's security footage.
...
By 2:50 p.m., the suspect had already bought a drink at a Subway restaurant inside a Walmart store and left on foot, four minutes before scanner traffic said the gunman was still on the second floor of the school.