Hamlin was a corrupt private investigator hired by Sal Maroni to investigate the identity and whereabouts of the Joker.


Hamlin was approached by crime lord Sal Maroni soon after the summit where the Joker first introduced himself to Gotham City's mob. Hamlin was requested to find out who the Joker was and where he lived.

After several days, Hamlin returned to Maroni, who was in the middle of a dinner in a high-end restaurant. Completely disheveled and mentally exhausted, Hamlin asked Maroni if he hadn't just imagined the Joker, because he could gather no leads on anything about him. Hamlin then began laughing hysterically and uncontrolably. He soon collapsed dead in the middle of the restaurant.

Maroni had an autopsy conducted on Hamlin's body. The person who conducted the autopsy informed Maroni that they had found traces of an herb originated from somewhere in Asia. Maroni couldn't, or didn't care to, remember just where.

Behind the scenesEdit

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In other mediaEdit

Hamlin was not covered on film, or referenced, in the events of The Dark Knight, nor any other media in the Nolan franchise.


  • Due to the nature and place of origin of the herb found in Hamlin's system, it seems to be suggested that the herb was the Blue Poppy, used in making Fear Toxin.
  • The symptoms of Hamlin's uncontrollable and hysterical laughter, coupled with the possible poisoning of Fear Toxin, seems to indicate that the Joker had caught wind of Hamlin's search for information on him, and then had food or a beverage that would be consumed by Hamlin tainted.
  • Whatever the herb, it may have been tainted to become Joker Poison.
  • The herb may have been untainted, and either related or unrelated to the Blue Poppy, yet naturally possessing the ability to cause the symptom of involuntary hysterical laughter.
  • Yet another possibility is that the Blue Poppy has the natural ability, without tampering, to create hysteria if ingested frequently, or in large enough portions.