Were the Uvalde police cowards?

I’ve read several different accounts of what the Uvalde police did (or didn’t do) that delayed any possibility of rescue of the kids ar Robb School.

One account says “they didn’t want to get shot at” and so they held back.

Another report was that “they thought the killing was over”.

A different one said “they were waiting for better equipment to arrive”.

None of those are persuasive to me, when a gunman is shooting up a classroom.

What sort of courage did the local police display?