Banded coral shrimp attacking fish?

[conkyy]

Like the title says, it climbed up on a decoration and tried to grab a new fish. Do I have a lunny shrimp or something?

[conkyy]

I put a minnow in there to distract him, which he is currently eating. He tried to grab it and got it once it started floundering.
This is in my 30 gallon tank.

[hackteck]

some of them are very aggressive

[conkyy]

Well the next morning he was doing ok, around 10 am he was dead. The shrimp didn't get him tho. I have been having fits adding fish to both tanks. This one has had perfect parameters. Is there a disease that kills fish in 24 hours but doesn't hurt whats in the tank already?