Peralta was running an illegal fight ring for the Cabal, pitting abnormal against abnormal. They kidnapped people and made them into abnormals using a Scarab to control their mind and a drug called 'the juice' to trigger/ maintain the abnormal transformation. 54 meta-human fighters, 19 of which died in the ring, were created. The Cabal was attempting to make a super human army.
When Magnus and her team discovered the location of the ring Peralta tried to run. He was confronted by Magnus while trying to empty his safe. She let him go with a message and a warning for the Cabal.