Only if they can prove you knew the money was dirty.
How they are going to prove that. Normally in localbitcoins.com, there is hardly any one-to-one conversation between the buyer and the seller. But even then, if some of the potential buyers tell me that the coins are indeed meant to buy drugs or ammo, I'll tell them to GTFO.
The police told the sellers it was going to be used for dodgy shit.