|Title|| Police Officer|
|Division||365th M.P. Brigade|
|Occupation||Police Officer; Army Reservist|
|Family||Jamie Callahan (wife)|
During his time in the Army, Callahan spent time overseas in Afghanistan, where he took an anti-malaria drug called Quinium. The drug affected him very badly, and upon returning home, his wife Jamie and partner Kristen Vaill both noticed a distinct change in his behavior. In 2005, he raped Jamie, and she called the police, which brought the couple to the attention of the Manhattan Special Victims Unit. During their investigation, the SVU was unable to determine one way or the other whether Tommy had raped Jamie or whether the sex between them had been consensual.
However, his commanding officer, Captain Barbara Pierce, intended to assign him to desk duty, and he flipped out when he was asked to turn in his weapon, attacking Captain Pierce and slamming her onto a desk. He was immediately committed to a psychiatric ward for observation, though an examination by Doctor George Huang initially failed to discern the cause of his behavior. The drugs he received in the psych ward helped him to regain his sanity, but he was horrified by what he'd done. As a result, he committed suicide by smashing his skull against a concrete wall. (SVU: "Goliath")
- Jamie Callahan (his wife; raped)
- Captain Barbara Pierce (his commanding officer; assaulted)