They have already publicly admitted he was hiding outside behind his car, and he has stepped down and retired.
There were 3 MORE local police that arrived to join him in hiding.
They were only flushed out and spurred to action when a neighboring police department showed up, if I remember correctly.
No video of the shooting, but one kid interviewed by local news immediately afterwards claimed she saw and spoke with Cruz (alleged shooter) in the hallways, while hearing shots coming from somewhere else.
Indicates maybe that they dumped a dazed Cruz off at the school, and a shooter or team of shooters did the actual killing.
A teacher also claimed to see the shooter, who had "full metal" gear on.