|Affiliation||United States Army|
|Division||U.S. Army Rangers|
|Occupation|| Former soldier|
|First Appearance||"Traumatic Wound"|
Frank Patterson is a U.S. Army veteran who suffers from PTSD and was a key witness in the gang-rape of a young girl named Gabby Shaw.
While working as a bouncer at a concert, the use of fireworks causes Frank to undergo a PTSD episode. He sees Gabby being gang-raped, mistakes her for a female soldier, and tries to protect her by jumping on top of her. When the SVU detectives arrive, they questioned him and Gabby's friends as to what had happened. Later on, while she is going over pictures with the detectives, Gabby tells them that Frank was on top of her. When Nick Amaro and Amanda Rollins go to find Frank, they tell him what Gabby said and he flees but is caught. They then bring him in for interrogation, during which Rollins accidentally puts words in his mouth. While he and the other suspects are being led into a police car, Frank has another PTSD episode. This causes a brief squabble, during which Amaro figures out he has PTSD. He subsequently brings him back into the precinct.
While Frank is in the holding cell, Amaro comes in with him and reveals that he was a veteran. Frank tells him how he was once tried to save a fellow female soldier by covering her with his body. It is then discovered that he believed Gabby was a female soldier and that he was trying to protect her. He also tells that he saw the person who pulled Gabby's shirt down, who later turned out to be Ralph Priatti. The next day, he is released. When it is discovered that Gabby's friends conspired to have her gang-raped, Frank serves as a key witness for A.D.A. Rafael Barba. During cross-examination, the suspects' attorney Lester Cohen tries to use Frank's fragmented memory to discredit him, which eventually causes Frank to remember that there was someone with military-style cut hair who took a video of the gang-rape. Cohen then asks for Frank to be struck down as a witness, but Barba asks for time to find the video. When the detectives find Ralph's brother Louis, they also find the video. When it is used as evidence, all three defendants plead guilty to conspiracy to commit aggravated sexual assault. (SVU: "Traumatic Wound")