- "I don't... have to do anything. I'm free. You know the funny thing? I think it was my time in Arkham that freed me. I mean, in here. Now I see the world for what it really is. An abandoned factory full of broken machines. Some... very few... can be fixed. Most... just have to be scrapped."
- —Jack Buchinsky[src]
Prior to being admitted at Arkham Asylum, Buchinsky was the brain behind a series of violent bank robberies that cost six bystanders their lives. He worked with a group of accomplices, none of whom were ever identified. After being arrested because of a stroke of luck on the Gotham City Police Department's part, he reached out to his employer, Salvatore Maroni, and got himself admitted to Arkham Asylum under the alias "Jack Gruber".
Escape from Arkham
Jack Buchinksy began performing electro-therapy experiments on several inmates of Arkham Asylum. These failed experiments resulted in one inmate becoming brain dead, and another forced to constantly recite William Shakespeare quotes on a loop due to brain damage. The discovery of these inmates led to Jim Gordon, who was placed as a security guard at Arkham for his actions as a police detective, to contact the GCPD. The GCPD began investigating the asylum in an attempt to find out who was behind the experiments. The GCPD deduced that a female inmate from Arkham named Dorothy Duncan had been posing as an asylum nurse. The GCPD believed that Duncan was behind the experiments but, before they could arrive, Duncan freed all of the inmates from their cells but was killed in the process. The riot was eventually contained and the inmates were placed back in their cells.
Elsewhere, Buchinsky finally performed a successful experiment on a brutish inmate named Aaron Danzig, who now obeyed Buchinsky's every command. Buchinsky used Danzig to kill Gerry Lang and help him escape the asylum.
After escaping Arkham, Buchinsky began tracking down and murdering some of the people who had betrayed him when he was arrested. Buchinsky tracked down some of his old electrical equipment at an old warehouse and began making plans to murder Sal Maroni.
In an attempt to get his old position back at the GCPD, Jim Gordon offered to help the police capture Buchinsky, now aware of his true identity. Commissioner Gillian Loeb told Gordon that if he could capture Buchinsky within 24 hours, Gordon would be reinstated at the GCPD.
Predicting that Buchinsky would target Maroni, Gordon took Maroni into protective custody in order to lure Buchinsky and Danzig to the police headquarters. Buckinsky arrived and used his electrical equipment to send everyone in the building into an unconscious state, with the exception of Gordon, who was wearing protective rubber. Upon subduing Danzig in a fistfight, Gordon turned his attention to Buchinsky, who was about to attack with his electrical devices. With no other options, Gordon threw the liquid in a nearby coffee mug on Buchinsky's devices, causing them to malfunction. Buchinsky was then arrested by the GCPD.
- "Buchinsky is crazy and arrogant and resourceful. Wherever Maroni is, he'll come after him. He'll enjoy the challenge."
- —Jim Gordon to Harvey Bullock[src]
Buchinsky is a crazed and vengeful electrician, but nonetheless highly intelligent and formidably deceptive.
- Genius-level intellect/Master tactician: Jack has shown to be a highly intelligent individual as was he was able to get himself put in Arkham and while in there, he performed a series of electro-convulsive experiments on the inmates with the goal of controlling one of them so as to escape.
- Electronics expert: Jack was able to tamper with the GCPD's electrical system in a way that he was able to electrocute and render everyone unconscious, with the exception of Gordon.
- Expert engineer: Jack is an expert at engineering his electrical weaponry, such as his Electrocutioner suit and the electric energy bomb he used on Maroni and his gang.
- Master of deception: While he was in Arkham, Jack made it seem as if he was innocent of the crimes he committed in there prior to his escape, such as when he was being interrogated by Gordon.
- In DC Comics, "Electrocutioner" is a legacy name used by three separate anti-heroes and supervillains with electricity-based technology. The original was an executioner of criminals who was eventually shot down by the vigilante Adrian Chase. The second was an unidentified criminal who made a single appearance in Detective Comics #626. The third and most prevalent is Lester Buchinsky, a vigilante-turned-supervillain and the brother of the original Electrocutioner.
- Given the common surname with Lester Buchinsky, Jack Buchinsky is very likely based on the original Electrocutioner.
- Jack Buchinsky's anticlimactic defeat in Gotham is very similar to Lester's joke boss fight in Batman: Arkham Origins.