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What Happened to Samuel Hunt's Greg “Mouse” Gerwitz on Chicago P.D.?
The Intelligence Unit's former tech wizard was a fan favorite during the early days of P.D.
Greg "Mouse" Gerwitz may have appeared in the early seasons of Chicago P.D., but his faultless empathy, tech expertise, and powerful storyline as a veteran made him an unforgettable member of the Intelligence Unit.
Appearing in the first four seasons across 35 episodes, Mouse was the Intelligence Unit's tech expert for several seasons of P.D. action. Recruited to the unit by his dear friend and former comrade Detective Jay Halstead (Jesse Lee Soffer), Mouse boasted a unique backstory that resonated with viewers. Mouse's blend of tech-savvy and heartfelt loyalty soon made him a P.D. fan favorite. Even years after his exit, Mouse still holds a place in Chi-Hard's hearts thanks to Hunt's lasting impression as the Intelligence Unit renegade turned techie.
RELATED: What Happened to Jesse Lee Soffer's Detective Jay Halstead on Chicago P.D.?
While his P.D. tenure was brief, Mouse was a certified scene stealer in the squad room and an unforgettable addition to the Intelligence Unit. Let's look back at some of Mouse's biggest P.D. highlights that cemented him as a One Chicago icon.
Who was Greg "Mouse" Gerwitz on Chicago P.D.?
Greg "Mouse" Gerwitz made his first appearance in the Chicago P.D. Season 1 finale ("A Beautiful Friendship") as a close friend and criminal informant for Jay Halstead. The two men were quite close, but fans didn't learn the extent of their bond until his reintroduction in Season 2, Episode 16 ("What Puts You On That Ledge") when Halstead recommended Mouse for a job in the Intelligence Unit as the squad's go-to tech expert, helping the detectives track down offenders.
Halstead put in a good word to Hank Voight (Jason Beghe), telling his commander that he trusted Mouse with his life. Before Voight would recruit Mouse, the newbie needed to earn the approval of the no-nonsense Desk Sergeant Trudy Platt (Amy Morton). After a grueling interrogation from Trudy, we learned that Mouse was in the military before being medically discharged. Despite some rough questioning, Trudy gave her blessing, and Mouse scored the Intelligence Unit tech job.
Upon his hiring, it didn't take long for Chi-Hards to learn Mouse and Jay first met as part of the same unit when they were deployed to Afghanistan and saw some intense action together as Army Rangers. Mouse commended Halstead for keeping his life together while he "fell apart" after service, falling into drug addiction and catching several charges for hacking and theft.
Despite his tumultuous return from service, Mouse quickly cemented himself as an asset to the Intelligence Unit, showcasing indomitable technical finesse on investigations. Whether tracking a car GPS or jamming a cell signal, Mouse was the unit's ace-in-the-hole on several cases throughout Seasons 2-4. He may have stolen a truck full of Blu-Ray players and hacked into a Department of Defense satellite once upon a time, but he more than made up for his misdeeds with several years of criminal butt-kicking on P.D.
Mouse and Jay Halstead's Bond on Chicago P.D.
After joining the Intelligence Unit alongside his close friend, Halstead and Mouse's relationship quickly became a One Chicago obsession. While Halstead had a steel wall up around his loved ones, Mouse was deeply impacted by his time in the army, often expressing remorse surrounding the action he saw there. Through these moments of recollection with Halstead, it was clear that Mouse was much more reflective of his army days, while Halstead preferred to sweep those harrowing memories under the rug. Following their medical discharge following a horrific bombing, Mouse and Halstead grew even closer after they readjusted to civilian life and processed the PTSD of their time overseas together.
Mouse's PTSD had rippling consequences in his personal life; after falling into drug abuse, he found himself unable to hold down a job. Halstead helped him become a criminal informant until his Intelligence Unit recruitment. Halstead always had Mouse's back, which is why when Mouse was held hostage by a gunman in Season 3, Episode 3 ("Actual Physical Violence"), Halstead nearly killed a man.
RELATED: Jesse Lee Soffer Reveals Why He Left Chicago P.D.
A tragic victim of opportunity, Mouse was taken hostage by a furious father who targeted the CPD after his daughter remained missing — Mouse was the first non-civilian he'd spotted in the district. Halstead was inches away from taking out the gunman, but after Mouse expertly de-escalated the situation, he was able to turn the gun on the father, allowing the cops to take him into custody. However, Mouse quickly noticed this wasn't a typical criminal — he was a desperate father torn apart by grief.
Mouse visited the gunman in custody and promised him he'd find his daughter. Additionally, Mouse took out the bullets in the gun before handing it off to evidence. After tracking down the man's daughter and tampering with evidence, Mouse managed to reunite the family after the man's charges were reduced to reckless endangerment. Mouse was mums the word when questioned by Voight but later confessed his manipulations to Halstead over a beer.
Why did Mouse leave the 21st District on Chicago P.D.?
In Season 4, Episode 2 ("Made a Wrong Turn"), Mouse expressed interest in returning to the Army Rangers, a motion that Jay Halstead found upsetting. Halstead — aware of how Mouse's time in the service traumatized him — feared that his best friend would return to a troublesome existence if he reenlisted and encouraged Mouse to become a police officer instead. Mouse shrugged this idea off, telling his friend that he was born to be a soldier.
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Recalibrating, Halstead indicated Mouse's criminal record as reasoning for not returning: the army wouldn't allow him to reenlist with the charges he'd accrued. Mouse asked Voight for help clearing his record, an idea he considered until Halstead intercepted the plan, leading Halstead and Mouse to come to blows during an argument in the bullpen in Season 4, Episode 5 ("A War Zone"). Halstead continued to express frustration even after Mouse was offered a position in his old unit. Mouse argued that he'd only ever asked for one thing while serving with the Intelligence Unit. Yet, everyone refused him when he needed this favor.
After the fight was broken up, Halstead realized that he'd been projecting his own trauma from the army onto his friend. After coming to his senses, Halstead asked Platt to clear up Mouse's record and gave his friend his blessing as he explored a new chapter outside the Intelligence Unit.
