I'd get rid of the shrimp.
IME, yes, they are killers and I'm never buying any more of those little scavaging savages.
I've posted before that I suspected they were killing my otos. I don't think anyone believes me, tho
I saw one attack a kuhlii and a corycat a while back and I saw one attack another cory tonight. I've found a few dead otos with their eyes missing and one dead corycat with missing eyes. I saw a shrimp swim down from the top of my tank with a dead oto in its claws. The oto had no eyes.
They sit on top of my big rock and wait for a fish to swim below and stop. Then they grab at them. Hate 'em.
I rounded all of them up and put them in my son's silver dollar tank. Mr. Cleaner, the Hammer's Cobalt Blue lobster lives in there. He hasn't touched them (typical!), but some day he might. I hope.
Roan