Fan Casting "The new inmate" in Batman: Black, White, and Vengeance

After the final battle is over and both Joker and Harley Quinn, alongside their army of mercenaries and serial killers, have been arrested, Bruce receives word a new prisoner being taken from Metropolis to Gotham. Curious, Batman visits this new prisoner and immediately recognizes him, asking multiple questions, including how he ended up here in the first place. But this man only tells Bruce to "check the news", referring to something that occurred in Metropolis while Batman was fighting Arthur Fleck in Gotham City.