What Would Be the Best Way to Get a Charge Dismissed in This Scenario

My question involves criminal law for the state of: Ohio

A hypothetical scenario -- the police are conspiring to deprive the rights of a party A. They send an informant, Party B, to carry out a 'hit.' Party B sees Party A walking down the street and runs up and starts assaulting Party A with a baseball bat. Party A falls to the ground and starts flailing at Party B on the ground, swinging at him while being clobbered with the baseball bat. The cop shows up and sees Party A flailing at the informant on the ground while being struck with the bat. Rather than arrest the guy with the baseball bat, the cop arrests Party A for assault on an informant. The cop conceals all the informant's offenses from his probable cause affidavit. What are the available defenses in this scenario and what would be the best defense to get the charge dismissed before plea or trial?

Would a lack of probable cause defense (concealment of material facts) work for getting the charge dismissed before plea or trial? Would unlawful search and seizure (all evidence criminally obtained) work in getting the charge dismissed before plea or trial?

What Would Be the Best Way to Get a Charge Dismissed in This Scenario