Art Mullen is the Chief Deputy of Lexington US Marshals Field Office in Lexington, Kentucky. He is portrayed by starring cast member Nick Searcy.
A native of Harlan County, he met another former resident, Raylan Givens, who was also an instructor at the US Marshal's Academy at Glynco, Georgia.
He takes a lax attitude towards Raylan Given's unusual method of law enforcement thinking that, in time, either Raylan leaves Harlan County for good or becomes another US Marshal killed in the line of duty.
In "Blaze Of Glory", Art Mullen is nostalgic for his first major case as a Marshal, the Frank Reasoner case, where Reasoner, some 40 years before, committed a string of Bank Robberies all over Kentucky before he was put away in Federal Prison. And when Reasoner resumes his activities before dying off, this time with a crew of younger toughs under his wing, Mullen commits to catching Frank Reasoner and his gang one last time. As the two old men chase each other at the airport, Mullen tells Reasoner about how his case forty years ago was Mullen's first big case as a Marshal...and here they were, both 40 years older, with Reasoner needing portable oxygen to move around while Mullen is now wearing hearing aids in his ears.
In "Where's Waldo?", he is seen talking to a US Marshal named Patrick Massett, who is interested in succeeding Art when he retires. Art, realizing the man's true interest, gives him a quick analysis of Tim, Rachel, and Raylan. Art excuses himself, saying that he has to inform Raylan that his father, who killed a cop has now killed a prison inmate. Art informs Raylan, who mentions that the murder probably had something to do with the bag he found in the wall, and confides the information to Art. Art, Tim, and Raylan leave and stake out the Truth residence, where they give chase after the Truth's grandson Milo, after they spot him checking the mail. In the house, they learn that the man posing as Waldo Truth is really an imposter named Harold Shawn, who has posed as Waldo for 15 years to provide the Truth family with disability checks. Mother Truth mentions that Waldo left with a pilot named Drew Thompson, but never returned. Art suddenly wants to leave after hearing Drew's name. Art explains to Raylan and Tim how Drew, the pilot, once parachuted into a local neighborhood and brought cocaine with him. Yet new evidence—a scar on the body consistent with one that Waldo received from his loving wife—points to the body found in the neighborhood as belonging to Waldo. So all these years Drew has been presumed dead, but it was Waldo all along. So where's Drew? "I don't know, but I bet your daddy knows," Art tells Raylan.
In "Kin", he is seen standing along with David Vasquez when FBI Agent Jeremy Barkley enters, angered at the Marshals for taking over the Drew Thompson case. Art tells him that they petitioned the Department of Justice in order to do so.
In "Money Trap", he talks to Raylan and tells him to offer Arlo a deal to find Drew Thompson, much to Raylan's chagrin. Later, he calls Raylan while he is with Jackie, and has suspicions of her being a new love interest for him.
In "Outlaw", he informs Raylan of Arlo's stabbing. Later, upon learning of Arlo's death from Raylan, tries to give Raylan a week off. Raylan argues against this and Art negotiates with him, giving him two days off.
In "Get Drew", Art shows up at the roadblock and objects to Raylan wanting to inform the state troopers after they realize that Ellen May is with Shelby. Art would rather the Marshals catch someone who is a huge badass like Shelby than allow the state troopers to do so. Later, Art is seen with Tim, Raylan, and Rachel when they drive to the abandoned field after being tipped off by Johnny Crowder.
In "Decoy", Art and Tim (along with Nelson Dunlop--masquerading as Raylan Givens--and the KSP Officers) drive to the meeting place along the highway. Tim, who notices two abandoned cars parked too closely to one another and soon a third, becomes suspicious of a set up and stops the cruiser. Tim then drives around, parking besides the KSP truck to avoid moving around the bombs. Later, they arrive at the high school where they learn from Bob Sweeney that Shelby has escaped Harlan by means of a coal train.
In "Peace of Mind", Art and Raylan learn that Shelby refuses to go through with his deal for WitSec until he knows for sure that Ellen May will be safe and protected as well. Art still shows interest in suspending Raylan, but Raylan argues that he wants to finish what he started and wants to look for Ellen May. Art reluctantly agrees under the condition that Raylan takes Tim and Rachel with him.
In "Ghosts" Art shows up at Raylan's house after the shooting and tells Raylan that he can't work the case because it is too personal for him, and warns Raylan not to bother coming back to the Marshals office if he goes over to Nick Augustine himself. Later, he calls Raylan to inform him that Sammy Tonin is the new head of the Detroit mob, and that Augustine was killed in a mob-style execution.
In "Good Intentions", Art calls Raylan to let him know that Charles Monroe is likely to be released from jail and may come looking for him. Art also assigns Rachel to stay at the Monroe estate with Raylan after he is threatened by Henry Granger.
In "Over the Mountain", Art assigns Tim and Raylan to look for Wade Messer, who was a confidential informant for Boyd Crowder's ongoings. Ed Kirkland calls Art and says that he has more than a tidbit of information on Sammy's whereabouts and they set up a meet in Detroit that night. Art talks to the arrest Canadian 2, an associate of Sammy's. He tells Art that Sammy talked about having a Kentucky lawman in his pocket who was present the night of Augustine's murder.
In "Shot All to Hell", Art waits outside of a diner that Ethan Picker, Wynn Duffy and Mike are inside of and notices that Elias Marcos is also waiting. After a brief standoff between the two men, Marcos leaves and Art enters the diner. Just as Art is ready to detain Picker and take him back to the Marshals office, Marcos enters the diner, saying that he is there to give Picker a ride. Art tells Marcos to leave in 10 seconds or he will shoot him. At the Marshals office, Raylan coerces Picker into giving up Marcos's location, where they track him down to a shipping warehouse. Marcos ambushes them with an AA-12 Automatic Shotgun, and as he is reloading, Raylan sneaks behind crates and shoots Marcos in the chest, killing him. Art is bummed that their only connection to Theo is dead, but Art, Raylan and the Marshals find Theo hiding out in a shipping container, with a gunshot wound in his abdomen. Art is praised at the Marshals office for capturing Theo, and Vasquez congratulates him. Before departing, Vasquez tells Art and Raylan the story about the Kentucky lawman being present at the time of Augustine's murder, and tells them that Picker revealed the lawman was corrupt FBI agent Jerry Barkley. Raylan tells Art for a fact that Barkley was not the one present when Augustine was killed, leaving it open ended as to whether or not Raylan is confessing.
In "Kill the Messenger", Art is seen drinking in a bar when Raylan shows up. After coldly staring Raylan down, Art punches him in the face before departing.
In "Raw Deal", Raylan talks to Art in his office as he is tired of Art treating him like shit ever since the situation of Augustine's murder and wants to be treated like a US Marshal. Raylan requests being transferred from Kentucky as soon as he comes back from visiting his daughter in Florida.
- Leslie Mullen: Wife
- Raylan Givens: Longtime Friend and Subordinate
- Tim Gutterson: Subordinate
- Rachel Brooks: Subordinate
- "Do you dumb ass peckerwoods understand english? On the ground hillbillies! Now!" - Yelled from a bullhorn as the Marshalls raid Bennet Family compound in "Bloody Harlan"
- (To Raylan) " Next time you say you're not good at something I'm going to believe you." in "Guy Walks Into a Bar"
- "Well he's a bank robber Raylan, why would he lie to me?" in "Save My Love"
- "Well then you look like you are some drunk who is looking for some car keys under a street lamp cuz that's where the lights is" in "The lord of war and thunder"
- "The first thing were going to do is acknowledge that this guy is awesome, I mean he shoots Theo Tonin, fakes his own death in a spectacular fashion, pushes a guy out of a airplane, while he's flying it, parachutes in to Harlan county with enough coke and cash to jump start the economy of a small country, and then he has the balls to get a job in law enforcement, not once but two times, he spends a couple of days riding around with you (Raylen) while you're looking for him, and now he's run off with a hooker that's half his age....that's some badass shit!"
|Season one appearances|
|Fire in the Hole||Riverbrook||Fixer||Long in the Tooth||The Lord of War and Thunder|
|The Collection||Blind Spot||Blowback||Hatless||The Hammer|
|Veterans||Fathers and Sons||Bulletville|
|Season two appearances|
|The Moonshine War||The Life Inside||The I of the Storm||For Blood or Money||Cottonmouth|
|Blaze of Glory||Save My Love||The Spoil||Brother's Keeper||Debts and Accounts|
|Full Commitment||Reckoning||Bloody Harlan|
|Season three appearances|
|The Gunfighter||Cut Ties||Harlan Roulette||The Devil You Know||Thick as Mud|
|When the Guns Come Out||The Man Behind The Curtain||Watching the Detectives||Loose Ends||Guy Walks Into a Bar|
|Season four appearances|
|Hole in the Wall||Where's Waldo?||Truth and Consequences||This Bird Has Flown||Kin|
|Foot Chase||Money Trap||Outlaw||The Hatchet Tour||Get Drew|
|Decoy||Peace of Mind||Ghosts|
|Season five appearances|
|A Murder of Crowes||The Kids Aren't All Right||Good Intentions||Over the Mountain||Shot All to Hell|
|Kill the Messenger||Raw Deal||Whistle Past the Graveyard||Wrong Roads||Weight|