Matthew Casey

In the pilot, Casey and Kelly Severide are shown to be good friends since their days at the fire academy and long-time coworkers who are at loggerheads with each other, much to Chief Boden's frustration, over the death of fellow firefighter and close friend Andy Darden due to a bad call. Although they try to remain professional in front of their men, their spats often make their way into the firehouse off duty to the point where they indirectly insult each other, with newest candidate Peter Mills getting caught in the crossfire. They eventually put aside their animosity by the end of the first season. Throughout the show they are often seen putting themselves in danger to assist one another during dangerous calls. Both are known to their men as intensely guarded and reticent about their personal lives but they confide in one another, usually over a beer or sharing a smoke on the firehouse roof.

Darden's death affects Casey in the following episodes as he is forced to look after Darden's two young sons when Darden's widow Heather is imprisoned for DUI manslaughter. He discovers that he was named their legal guardian in the Dardens' will, and their time together helps develop a strong relationship with the boys.[9] The fact that Heather still keeps in contact with Casey is a sore point for him and Severide as she blames Severide for failing to prevent her husband's death.[10]

Casey is engaged to Dr. Hallie Thomas for a time, but she tells him she never wants to have children (in contrast to his desire for them) and they decide to break it off. He tentatively pursues Gabby Dawson but they end up staying friends. At the end of the first season in "Ambition", Hallie returns and Casey rekindles his relationship with her. After discovering a drug ring in a clinic where she works, she is murdered in the season 1 episode "Leaders Lead". Despite Casey and Severide’s efforts to rescue her from the fire set at her clinic, Casey is told by a doctor that Hallie has died, and he begins weeping in Mills’ arms. At the end of season 1 and the prelude into season 2, Gabby shows up at his door helping him cope with Hallie's death. She has for a long time had a crush on him, but on a casual date at her cousin's Christmas party, he "kissed her on the cheek" when she tried to kiss him, and from then on Dawson seems mad at him. In the season 2 episode "Rhymes with Shout" he shows up at Gabby's door and kisses her. At the start of the next episode, they are shown waking up in bed together. In the season 2 episode "Not Like This", Casey risks his life to save a baby in a burning building and is rushed to the hospital in critical condition. When he gets back on the job, he suffers from neurological symptoms such as memory loss, uncharacteristic outbursts of anger and headaches but keeps this from his colleagues, although his erratic behavior is quickly picked up by several veteran coworkers and Dawson. When he begins to bleed from his ear, he sees a doctor who tells him that it was caused by a crack in his skull and warns him that another hit to the head could be catastrophic. He decides not to tell his colleagues or the Chief, fearing that he would be forced into disability retirement.

After Mills breaks up with Dawson for various reasons (one being Dawson’s feelings for Casey), Dawson and Casey begin to spend more time together, partially because Casey has to look after Heather's children (even with his 24-hour shifts) and asks for help. After spending more time together, Casey and Dawson decide for the moment they are happy just being friends. Casey eventually gets helps from Dawson's friend, Isabella, to get Heather moved to a minimum security facility so that she can see Griffin and Ben more often. In the episode "No Regrets", Heather gets released due to overcrowding and she moves to Florida because she can't live in Chicago without being reminded of both her husband and friend's death. This deeply saddens Casey, but he understands. In the episode "You Will Hurt Him", Casey and Dawson wake up in bed together. Dawson still has doubts and fears about Casey's commitment but tells her, "I had a chance at this a year ago and I blew it. I've been regretting it ever since." He further assures his commitment by telling her "As far as I'm concerned, it's our time now." They kiss and start a relationship. He proposes to her in the season two finale "Real Never Waits", but before he can get an answer the bells go off and they head to a call at which Shay is killed. This puts off his plans for a while but months later in "Wow Me", Casey proposes to Dawson again at the Fire academy, and she happily says "yes" even before he can finish the question. The two then go home to have sex. However their happiness is short lived because Dawson joins Truck 81 and therefore as coworkers they can not get married. In "Nobody Touches Anything", the two share how they would do anything if they could get married now and seal it with a kiss. This is also short-lived because after they are caught kissing, things go downhill for the couple. Following Shay's death, Severide moves in with Casey and Dawson. Some of the strain on Casey's and Dawson's relationship comes from Casey's and Severide's relationship; with Casey putting Severide in front of Dawson. This, amongst other things, leads Dawson to break up with Casey in "Let Him Die". In "Headlong Toward Disaster", Severide turns down an order from his chief to spy on Casey. He also tells the chief that Casey is "one of the finest firefighters [he's] ever had the opportunity to work with in the entire CFD." Severide is the only person on the show, besides Dawson and Chief Boden, to call Casey by his first name. Casey is the only person on the show to call Severide by the nickname, Sev, while Severide is the only person on the show to call Casey by the nickname, Case.

In the Season 3 episode "Category 5", Casey knowingly turns down Voight's help (hinting that there are still tensions between him and Voight) with a case of human trafficking that involves the owner of a strip club, Jack Nesbitt. Nesbitt is a former firefighter and friend and Casey initially takes on construction as a favor but senses that something is not right about some of Nesbitt's "business associates". He eventually agrees to help Voight get intel about Nesbitt. In the season finale, "Spartacus", he is discovered missing when Dawson goes to his house to check on him. She finds his apartment trashed and torn apart and the dead body of a stripper named Katya who had worked for Nesbitt's strip club. Casey is nowhere to be found, presumably kidnapped.[5]

It is revealed that Katya had been compiling a notebook of evidence with the intention of exposing the trafficking ring running out of Nesbitt's nightclub. She went to Casey's house to ask for help but they are ambushed by Bulgarian criminals who kill Katya on the spot. For the first several episodes, Casey is seen struggling to come to terms with Nesbitt's betrayal and having to witness a murder in his own home. His inner turmoil is somewhat assuaged when Dawson, who is temporarily on desk duty at the Office of Fire Investigation, reveals to him that she is pregnant with their child. They intended to keep the secret "in-house" but word eventually spreads to their colleagues, even to their contemporaries at the CPD,[11] but Dawson suffers a miscarriage.

Casey's relationship with Dawson became strained when they disagree over her decision to foster Louie, a boy they had rescued who had no listed next of kin. He comes to accept Louie, much to Dawson's delight. They push for an adoption but a judge tells him that their chances are slim due to the lack of evidence that they are in a committed relationship. In the 100th episode he and Dawson get married and file for the adoption together.[1] However, Louie's biological father files for custody, having just returned from a deployment in Afghanistan and having learned about Louie's existence recently. He succeeds as he is backed by his immediate family members.

In the season 5 finale "My Miracle", Casey's life is left hanging in the balance when he is trapped in a warehouse fire along with Herrmann, Mouch, Kidd, Otis, Severide and Kannell. His fate is not revealed until the season 6 premiere, and he calls Gabby "my miracle" in what looks like a goodbye speech to her as he is not sure if he will be able to get out.

In the season 6 premiere "It Wasn't Enough", Boden makes the call to open up the water cannon, ordering the men to take cover anyway they can. Casey is seen taking cover using a metal cabinet, as well as shielding a victim. When Boden finds Casey, he is passed out under the cabinet with his PASS alarm going off. The episode the jumps two months later where the firehouse looks to be at a memorial to his life. They are in dress blues for this, but it turns out Casey receives a medal of valor after the fire and he along with the rest of Firehouse 51 return to normal lives.

In "An Even Bigger Surprise", he is promoted to Captain after rescuing a suicidal mentally unstable person from jumping off a building. In "A Breaking Point", after rescuing Dawson from the collapsed parking garage, he is promoted to Captain. Uniformed personnel clap for him and Dawson and the two hug. In "Devil's Bargain" he snaps at Ramon and then gets in to it with Dawson. He also has come to blows with Severide after they decide how to get a patient down who is trapped in wire on a building.

In "Down Is Better", after having learned that Hope, Sylvie Brett's friend from Indiana, has forged a signature from a fire chief, Matt and Chief Boden dismiss her from the fire station. In "Slamigan", Casey and Dawson are awarded temporary foster guardian of Bria Jamison, a runaway teen who has an addict father and family members who want nothing to do with her. In "Law of the Jungle", in the middle of a call of a warehouse fire, Casey and Severide jump off the roof as it explodes. In "The F Is For", he and Severide jump into the river fully clothed, and while Casey swims and heads to the surface, Severide is injured, and Kidd rescues him. Casey is then comforted by Gabby, and Severide recovers.

In "The Strongest Among Us", Casey helps Gabby get Bria ready for prom. He decides they should have something good to remember so he lets Bria and her date ride in the Truck. After the truck leaves Gabby tells Matt she wants to start trying again which he agrees to. In "The Grand Gesture", after going to a doctor and finding out Gabby has a 10% chance of dying if she gets pregnant, he decides he doesn't want her getting pregnant. He brings up adoption and looks into it, which makes Gabby upset since she's afraid the same thing will happen that happened to Louie. After a fight in the last episode, Gabby tells Matt she'll be right back and goes to ask about a job in Puerto Rico while he stays home, not sure where his wife has gone. In "A Closer Eye", his wife Gabriela, comes back from Puerto Rico only for her to leave once and for all. In "Going to War", while fighting a apartment fire, Brett expresses blame to Casey for letting Gabby go, only for him to tell her that there was nothing anyone else could do.

In "The Solution to Everything", Casey tells Severide that he and Dawson are divorced.[12][13] He starts dating a reporter named Naomi but she tells him in "Inside These Walls" that she is going to Zurich. He is surprised but happy that she helped him deal with the departure of his ex wife.

In "You Choose", Brett helps Casey look for an apartment to live in following the fire that destroyed his old apartment. She finds what appears to be the 'perfect apartment', but Casey decides to move in with Severide following his breakup with Stella Kidd. In "Fault in Him", while on a call for a suicide attempt and getting a clear from one of the officers, he is ambushed by a gunman who had killed his brother. In "Move a Wall", as he deals with his post-traumatic stress stemming from the events, he takes it out on Herrmann when Ritter gets injured on a call.

Casey has appeared on Chicago P.D., mainly in cross-overs. Although he is on friendly terms with most characters, he has a notable grudge against Sgt. Hank Voight due to the fact that he was a victim of Voight's cover as a corrupt cop running with local gangs and was livid by Voight's cover-up of his son's DUI. The animosity has since faded some as Voight saved him from being shot by Jack Nesbitt in the nick of time and assisted Boden in several arson-related investigations. Matt even showed sympathy to Voight after the loss of his son, Justin.

• Chicago P.D.: "8:30 PM" (April 30, 2014)
• Chicago P.D.: "The Number of Rats" / Law & Order: Special Victims Unit: "Daydream Believer" (April 29, 2015)
• Chicago P.D.: "The Silos" (September 21, 2016)
• Chicago P.D.: "Don't Bury This Case" (January 3, 2017)
• Chicago Med: "Cold Front" (February 16, 2017)
• Chicago P.D.: "Profiles" (March 7, 2018)
• Chicago Med: "When To Let Go" (October 3, 2018)
• Chicago P.D.: "Good Men" (February 20, 2019)
• Chicago Med: "The Space Between Us" (March 27, 2019)
• Chicago Med: "We're Lost in the Dark" (October 2, 2019)