Though able to protect the right side of his face in time, the acid splashed against the left side of Dent's face and horribly disfigured it.
Unknown to anyone, Moroni managed to smuggle a hidden flask of acid into the court and threw it on Dent. During a trial, he questioned mob boss Sal Moroni in court. Once Gotham's District Attorney, Harvey Dent worked to arrest and convict Sal Moroni, a prominent mobster in the city.
" For your dying pleasure, we are serving the very same acid that made us the men we are today!" ―Two-Face to Batman and the security guard.