|Real name||Martin Joseph|
|Occupation||Blackgate Prison Warden|
|Based in||Gotham City|
|Height||5 ft 11 in|
Arkham Origins Blackgate
|Voice actor||Khary Paton|
Martin Joseph served as warden of Blackgate Prison during the rise of the Joker. Although he has a degree in criminology and spent a small amount time in police administration, he has never worked as a prison guard. Instead, he was hired for his administrative abilities, and tasked with finding ways to increase Blackgate's profitability.
While he did experience success, it came with a price. The amount of inmates increased dramatically while funding for maintenance was cut, causing the facility to fall into disrepair and disrepute. As time went on, several of his guards came into the payroll of criminals such as Black Mask and the Penguin, and criminals from those gangs were unafraid of being sent to prison.
Despite all this, Joseph himself did not have any criminal ties, but was merely trying to manage the difficult task with which he was set.