My brother's charges were dismissed because the cop didn't show up for the hearing. Can those charges be brought back up?

You said the charges were dismissed, then no, they cannot just bring those charges back up.

Hello mis:

If the charges were dismissed WITH prejudice, they CANNOT be brought up again.

However, if they were dismissed WITHOUT prejudice, they CAN bring them up again.

excon

As excon stated, it will all depend on how the judge dismissed the charges.
He should have went for a summary verdict of not quilty.

Normally when they do, it is done where they will not retry the case.
My gut feeling is if it was a very serious case they would have merely continued it,

I find it very unlikely the DA would try again.