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Assistant Chief Leo Mason is the Director, Office of Operations, of the Los Angeles Police Department (LAPD) during Major Crimes, Season 6.

The Director, Office of Operations (also known as Assistant Chief of Operations) is responsible for managing and coordinating all matters related to field law enforcement, special operations, and detective operations throughout the city.

During Season 5, Mason was the Commander in charge of the Criminal Intelligence Division. He was promoted to Assistant Chief at the very end of the Season 5 finale, “Shockwave, Part 2”​​.

Character Information[]

In “Quid Pro Quo”​​, Mason visited Capt. Sharon Raydor after he was informed by Wescott Global that Thomas Chandler's laptop had been removed from his residence and that it was currently in the Police Administration Building. Reason for that was because his Criminal Intelligence Division was helping Thomas Chandler develop new surveillance technology for the LAPD. Federal authorities allowed him to remove Wescott's confidential files from the computer but left everything else in place. This surprises Raydor because usually when Criminal Intelligence takes possession of evidence, no one ever sees it again. He says that Deputy Chief Winnie Davis is watching him as closely as she is watching Sharon Raydor, and he can't allow for the more classified element of the case throw Sharon off-track, implying he wants Sharon to become the new Assistant Chief.

As Raydor points out that Mason is very much in the running for Chief as well, he remarks that he likes where he is now, like Sharon likes where she is. He also proposes a deal to Sharon, if he is promoted to Assistant Chief he will let Sharon keep Major Crimes, and if Sharon becomes the new Chief, she will let Mason keep Criminal Intelligence. If they want to keep their jobs, they can not allow Chief Davis to be promoted to Assistant Chief as she would most definitely try to restructure the department and they could both be reassigned somewhere else. Raydor also points out that there is Deputy Chief Howard to consider as well, but he remarks that Chief Howard is out of the race as he would already have the job if he was being considered. During “Intersection”​​, both Mason and Sharon are interviewed for the position and Mason gives Sharon tips based on his own mistakes. He also helps the division in tracking the victim's cell phone during his bike ride to establish the victim's route for the purpose of possibly locating surveillance footage. He also mans the MCD's Mini-RACR for Capt. Raydor during the MCD's surveillance operation as Buzz Watson was providing support for them in the field.

In “Shockwave, Part 2”​​, Mason is promoted to the rank of Assistant Chief to replace Taylor, a promotion that leaves himself, Sharon and Fritz happy and relieved. Mason allows Fritz to resume his old rank of Deputy Chief in charge of the Special Operations Bureau and surprises Sharon with a promotion to Commander, a promotion that had been promised but ultimately denied to her when she took over Major Crimes. Mason implies that he intends to give her greater responsibility to go with the new rank and sits down with Sharon to discuss changing Major Crimes "into something better."

In “Sanctuary City, Part 1”​​, Mason declares the disappearance of three boys a "critical missing", despite them having been only missing for a few hours and assigns Major Crimes to the case. Mason coordinates closely with Major Crimes during the case, supplying them with the needed resources but sometimes clashing with Lt. Provenza by implying that Provenza's reluctance to take the case is due to racial differences and later berating Provenza for his impromptu media briefing. While Mason coordinates with Major Crimes in getting them the resources they need and oversees the case, he allows Sharon to take the lead and does not try to control the case beyond assigning it in the first place and berating Provenza's actions. Mason goes as far as to leave the decision about what to tell the media at one point to Sharon rather than removing the decision from her hands and acting on what he thinks is best.

In “Sanctuary City, Part 2”​​, Mason continues to help with the case of the St. Joseph's Three and reluctantly coordinates with the two hostile FBI agents. Mason follows the squad's lead on the case, making it clear that Commander Raydor has lead on the investigation and keeping from the FBI that they already have wiretaps in place when the squad hides that fact from the agents in front of him.

In “Sanctuary City, Part 4”​​, after Sharon's collapse, Mason is visibly shocked by Provenza's loss of temper towards the FBI, but ultimately chooses to back him up in kicking the FBI out of Major Crimes. He is also clearly as worried about Sharon's condition as the rest of the squad. Mason is able to negotiate with the FBI to get Ryan Rojas and Miguel Diaz released into LAPD custody and places Provenza in charge of Major Crimes temporarily until Sharon can return to duty. After Doctor Garza is found dead, Mason informs the squad of their new crime scene.

In “Sanctuary City, Part 5”​​, Mason continues to help with the investigation of the St. Joseph's Three and to coordinate with Agents Vega and Faye. However, Mason is far less cooperative with the FBI agents despite their apologies and shows sympathy for Miguel Diaz's perilous immigration status. After Doctor Alan Redmond is exposed as the culprit, Mason is shocked to realize that everything had happened because of one man and his affair with a married woman.

Mason attends Sharon's wedding to Andy Flynn. During the wedding, Camila comments on how Major Crimes really is like a family, something Mason confirms. Its implied by Mason that Camila is considering transferring to Major Crimes following the closing of the case surrounding the St. Joseph's Three.

In “Conspiracy Theory, Part 1”​​, Mason coordinates with Major Crimes following the murder of a high-profile lawyer. After the lawyer's son announces her death on TV, Mason notes that he had just made the case "a very Major Crime." Mason is surprised to learn of Michael Tao's work on Badge of Justice and reveals that his mother is a big fan. When their discussion about it is interrupted, Tao mouths to Mason to call him later about it. Mason expresses surprise that Sharon wants him to authorize overtime for the division to attend a restaurant opening, but Sharon is able to make a compelling case and Mason allows it.

In “Conspiracy Theory, Part 3”​​, Mason gets angry when Sharon makes a decision behind his back that could lead to a massive lawsuit. Instead of apologizing, Sharon is openly defiant with Mason who remains angry for some time. At the beginning of “Conspiracy Theory, Part 4”​​, Mason makes it clear he has no desire to see Sharon yet after her behavior. However, by the time that Sharon returns about six days later, Mason has calmed down and states that he is pleased to have her return. Mason appears not to reprimand Sharon who is forced to inform him of the seriousness of her condition.

After Sharon collapses again, Mason is one of the people who goes to the hospital with her. After learning that Sharon has died, Mason is as grief-stricken as everyone else present.

In “By Any Means, Part 1”​​ and “By Any Means, Part 2”​​, Lt. Provenza struggles with Mason following the murder of DDA Emma Rios. Mason shows a reluctance to treat Emma's drowning as a murder committed by Phillip Stroh and to commit more resources to the investigation though Mason becomes more cooperative when Gus reveals that he has seen Stroh in LA after spotting Stroh's picture on the murder board. Mason expresses anger at the amount of money Provenza is spending, but helps to identify who Gwendolyn Stroh now is. When Provenza starts suggesting more security details, Mason berates him over it until Provenza suggests combining Rusty and Gus' security detail which Mason agrees is a good idea.

In “By Any Means, Part 3”​​, Mason becomes more cooperative with the investigation into Stroh's victims, now convinced of the threat posed by Stroh. When the detectives bring forth proof of Stroh's accomplice bugging Major Crimes, Mason becomes argumentative over how to handle the situation until Buzz Watson speaks up. To everyone's shock, including Buzz's, Mason defers to him over Tao and Buzz is able to convince Mason of the low threat of misleading Dylan Baxter, pointing out that what Dylan accomplished could've been done by Buzz, Tao, or even Mason himself. Later, Mason admits that he hates waiting around but also recognizes that Provenza was correct all along and defers to Provenza's plan to take Stroh down. After Provenza states strongly that they intend to take Stroh down "by any means," Mason agrees with "by any means," implicitly giving Provenza permission to kill Stroh rather than arrest him.

At the end of a meeting with some of the Major Crimes detectives, Mason and Det. Julio Sanchez discuss an offer that Mason has made to Julio that he hasn't decided on yet. Lt. Tao reveals to Provenza that Mason has offered Julio a promotion to the rank of Lieutenant with an assignment in the Criminal Intelligence Division. As a single father, Julio's current job of working homicides is hard on him and the promotion will give Julio the chance to take a less dangerous and more administrative job.

In “By Any Means, Part 4”​​, Mason continues to aid with the search for Phillip Stroh, but insists on sending SOB with Major Crimes as backup after Dylan Baxter is located. Though Provenza disagrees due to his desire to have a chance to kill Stroh, Mason only agrees to allow Major Crimes to go in first while SOB acts as backup. Despite Mason's interference, Fritz makes it clear to Provenza that he doesn't intend to take Stroh alive either.

After Dylan's dossier points to Stroh flying out of the country, Mason personally leads the entire LAPD, aside from Provenza who coordinates from the murder room, to the Burbank airport. When talking on the phone with Provenza, Mason rudely ignores Rusty's insistence that Stroh is up to something with Tammy Bechtel and has Provenza take the call off of speaker phone as a result. Mason refuses to spare any officers to perform a safety check on Tammy, forcing Provenza and Buzz in his role as a Reserve Detective to go instead when Rusty decides to check it out himself with or without help.

Following Stroh's death, Mason conducts Julio's promotion ceremony and prompts Provenza to reveal that he has arranged for Buzz to attend the police academy and become an actual detective. In Provenza's speech, he lists Mason as one of the team that will keep Major Crimes great for years to come.


In his job, Mason has been shown to be highly intelligent and a capable leader. Mason is self-admittedly ambitious, but he is also patient and willing to let others have the spotlight while he waits for his chance to come. He is practical, recognizing the threat Deputy Chief Winnie Davis posed if she became Assistant Chief and was willing to make a deal with his rival Captain Sharon Raydor and even share tips from his own experiences to help ensure he or Sharon got the job instead.

On a personal level, Mason has a friendly, open demeanor. Even while on the job, he acts in a more casual manner towards those under his command unless the situation requires seriousness. Despite the seriousness of the situation facing himself and Sharon with Winnie Davis, Mason was trading jokes with Sharon alongside tips. Mason is a man of his word as shown with his not only keeping his deal with Sharon about the Assistant Chief's job, but taking the opportunity to expand her own role in the department and work more closely with her. Possibly due to his African-American heritage, Mason is well-aware of racial differences and is not afraid to call people out on perceived racism. Mason states a belief that "its always about race" during cases involving races other than Caucasian.

As Assistant Chief, Mason appears to maintain a much-less stern demeanor than Russell Taylor. Instead of taking command of a situation or interposing himself where he doesn't need to be, Mason appears to be content with acting in a support role and deferring to others, in particular Sharon under whose division the investigation fell. While willing to chastise those under him for their mistakes, such as Provenza holding an impromptu media briefing, Mason doesn't carry on once his point has been gotten across.

While reluctantly coordinating with two FBI agents, Mason made it clear that Sharon was in charge of the investigation, not the FBI or himself. He showed a willingness to trust Sharon's choices and even back her up when she failed to inform the FBI right in front of him of an important fact despite knowing the truth. In the situation with the hostile agents, Mason took on a more pacifying and compromising tone to try to keep the peace between both sides, negotiating something of a deal that satisfied both sides while also not compromising their investigation. Notably, while everyone else was generally frustrated and angry, Mason was the voice of reason and calm despite clearly being as unenthusiastic as everyone else to have the FBI agents there.

Mason can have a stern in demeanor if the situation requires it. He becomes enraged when the FBI fails to share their information that the boys were located in Mexico, knowing the LAPD were conducting a search for the boys on an "epic scale". He also shared insider information with the press in order to shine a light on Father Jonas' possible indiscretions, something he previously berated Lt. Provenza for doing, and referred to Bishop Calhoun a "bastard" after he showed no signs of cooperation with the LAPD.

While shocked by Provenza's actions towards the FBI, Mason chose to back him up. Later, Mason was reprimanding towards Provenza about his behavior, but not overly so. He went so far as to hear out Provenza's complaints before informing Provenza of what he had done to take care of the situation instead of just cutting him off, allowing Provenza the chance to vent his frustration without serious reprimand or interruption. When Sharon collapsed, Mason was as worried about her as the detectives under her command. When paramedics asked for Sharon's name, Mason went so far as to correct himself from calling her Commander Raydor and stated that her name was Sharon.

When Sharon openly defied Mason, he was enraged by her actions, reminding Sharon that he was in charge, not her. However, Sharon remained unrepentant and continued to defy Mason, angering him further. The next day, after Sharon called out of work, a visibly still-angry Mason made it clear that he had no desire to see her. By the time that Sharon returned about six days after their argument, Mason had calmed down and even stated that he was glad to see her back. Mason did not seem to reprimand Sharon, especially since she was proven right and was worried about her request for a leave of absence. After Sharon died, Mason was visibly grief-stricken by the news.

Following Sharon's death, Mason struggles with Provenza on a personal level due to Mason's refusal to believe that Stroh is behind the murder of DDA Emma Rios and to commit resources. At one point, Mason makes a comment that Provenza takes as an apology and doesn't reprimand Provenza's presumption. As the case continues and Provenza is proven right, Mason softens his stance towards Provenza and defers to him. While Mason initially worried about what will happen when Stroh goes to trial, he changes to agreeing to allow Provenza to take Stroh down "by any means," implicitly giving permission to kill Stroh rather than arrest him.

When Buzz Watson attempts to voice his opinion on a serious situation in “By Any Means, Part 3”, Mason prevents Tao from answering in his stead and instead hears out Buzz's opinion on the matter despite the fact that Buzz usually just "turns the lights on and off around here" as Buzz puts it. In doing so, Mason shows a willingness to hear out those under him no matter their ranking, though he essentially challenges Buzz to talk since Buzz had been so eager to speak up before. Having been reluctant to commit to the suggested course of action before, Buzz's assessment of the situation convinces Mason to go along with the idea.

Career information[]

Asst. Chief Mason in his uniform.​​​​

  • When in uniform, Mason can be seen wearing four service stripes on his uniform. Each stripe represents five years of service in the LAPD, meaning he has served for 20–24 years.
  • Not much is known about Mason's background in the LAPD other than that he served as the Commanding Officer of the Criminal Intelligence Division (CI). Based on the fact that Detective Camila Paige became a favorite of Mason's during her time in CI, and as she transferred to the Missing Persons Unit sometime between Season 4 and Season 5 of Major Crimes, Mason had to have been the Commanding Officer of CI for some time before that in order for her to make such a good impression on him (presumably from at least Season 3 of Major Crimes).

Medals and service awards worn by Chief Mason[]

As seen in “By Any Means, Part 1”:

Ribbon Award name and description
LAPD-Police-Distinguished-Service-Medal.png Police Distinguished Service Medal

The Police Distinguished Service Medal is the department's highest award for service and may be awarded to employees who distinguish themselves by performing exceptional service in a duty of great responsibility or of critical importance to law enforcement.

LAPD-Police-Medal-for-Heroism.png Police Medal

The Police Medal is an award for bravery, usually awarded to officers for individual acts of heroism in the line of duty, though not above and beyond the call of duty, as is required for the Medal of Valor.

LAPD-Police-Commission-Unit-Citation.png Police Commission Unit Citation

The Police Commission Unit Citation is the department's highest unit award and may be awarded to an organizational unit of the department for bravery or outstanding service by its members functioning as a team.

LAPD-Police-Meritorious-Service-Medal.png Police Meritorious Service Medal

The Police Meritorious Service Medal is awarded to employees who distinguish themselves by performing exceptional service in a duty of great responsibility or of critical importance to law enforcement, but to a lesser degree than required for the Police Distinguished Service Medal.

LAPD-Police-Meritorious-Unit-Citation.png Police Meritorious Unit Citation

The Police Meritorious Unit Citation may be awarded to an organizational unit of the department for bravery or outstanding service by its members functioning as a team, but to a lesser degree than required for the Police Commission Unit Citation.

LAPD-Human-Relations-Medal.png Human Relations Medal

The Human Relations Medal is awarded to officers who have in their day‑to‑day activities shown great compassion and have gone above and beyond the call of duty in their response to fellow human beings.

LAPD-Urban-Police-Rifle-Ribbon.png Urban Police Rifle Cadre Ribbon

Given to any LAPD officer who is qualified to use a Urban Police Rifle (usually a AR-15 variant chambered in .223)

LAPD-Detective-Service-Ribbon.png Detective Service Ribbon

5 years of service in investigative units as a Detective and/or Lieutenant.

LAPD-Shotgun-Slug-Ammunition-Ribbon.png Shotgun Slug Ammunition Cadre Ribbon

Given to any LAPD officer who is qualified to use slug ammunition in LAPD issued shotguns.

LAPD-1994-Earthquake-Ribbon.png 1994 Earthquake Ribbon

Given to any LAPD officer who saw service during the 1994 Northridge earthquake from January 17 to January 18, 1994.

LAPD-Democratic-National-Convention-Ribbon.png 2000 Democratic National Convention Ribbon

Given to any LAPD officer who saw service during the 2000 Democratic National Convention.


  • In “Quid Pro Quo”​​, Lt. Flynn thought that Mason was kind of irritating but rest of the division did not agree with his opinion. The rest of the division thought he was smart and good at his job, and DDA Hobbs even chimed in that he was young, energetic, and attractive. He was also shown to be technologically proficient.
  • Despite their rivalry for the position of Assistant Chief, Mason and Sharon Raydor are shown to possess a friendly relationship, trading tips and jokes in “Intersection”​​. While Mason admits to being ambitious, he says he can wait and he likes his life the way it is. Following his promotion in “Shockwave, Part 2”​​, his first act is to promote Sharon to Commander, a promotion she had been long denied, and he appeared interested in collaborating with her to make the LAPD better. During “Sanctuary City, Part 1”​​, Mason coordinates closely with Sharon and the two appear to have an easy working relationship, far easier than Sharon and Assistant Chief Russell Taylor. Notably, Mason defers to Sharon's command of the situation despite outranking her as its her division and people, acting in a supportive role rather than a command role.
  • Mason made three appearances as the Commander of the Criminal Intelligence Division. He was featured in “Quid Pro Quo”​​, “Intersection”​​, and “Shockwave, Part 2”​​, which is the episode he was promoted to Assistant Chief. In “Shockwave, Part 2”​​, after Fritz returns, he pulls Mason out of the room to talk privately and Mason is not seen again until he is revealed as the new Assistant Chief. This is possibly the moment he was given the job, off-screen after Fritz pulled him away, although Fritz held the role of Acting Assistant Chief until the case was solved.
  • In a deleted scene for “Intersection”​​ on the Major Crimes Season 5 DVD set, Andy Flynn asks if Mason really wants Sharon for his boss following her departure after he gives her some tips. In the scene, Mason indicates that he does in fact prefer the idea of Sharon being in charge, asking Andy in return "don't you?"
  • In “Sanctuary City, Part 2”​​, Provenza admits that Mason was right about something and Provenza was wrong. According to Provenza, the only other person Provenza has said that to is his wife, Patrice Perry.
  • Provenza's behavior towards Mason in “By Any Means, Part 1”​​ closely mirrors Provenza's behavior towards Sharon Raydor in “Reloaded”​​ after Sharon took command of the Major Crimes Division. Notably, Provenza makes a comment about being the incident commander that is almost exactly the same thing he said to Sharon when she arrived at the crime scene in the series premiere.
  • In “By Any Means, Part 3”, Buzz implies that Mason possesses a similar level of skill to Buzz himself and Tao in regards to computers, something that makes sense given Mason's former job as the head of the Criminal Intelligence Division. This is also implied by the skill he displays in using Buzz's equipment, effectively replacing Buzz during situations where Buzz has to be in the field and can't run his equipment personally.
  • Unlike his predecessors, Assistant Chief Mason was never seen wearing a suit while on-duty, instead he always wore his uniform. The only time Mason was seen in a suit was during Sharon Raydor's wedding to Andy Flynn.
Characters — Major Crimes
Sharon RaydorLouie ProvenzaAndy FlynnMichael TaoJulio SanchezAmy SykesWes NolanCamila PaigeBuzz WatsonRusty BeckRussell TaylorLeo MasonFritz HowardDr. Fernando MoralesAndrea HobbsKendall