Supervisory Special Agent Jack Garrett
Leader of the IRT, he leads the team in its cases involving crimes that target Americans outside the US.
- Action Dad
- Da Chief: He's the head of the IRT.
- Experienced Protagonist: He's an experienced FBI Agent. He's well-known in the international law enforcement community that on certain occasions, he's allowed to carry his sidearm in countries that forbid firearms.
- Omniglot: Speaks a variety of languages, including Japanese, Spanish, etc.
- White Male Lead: Jack's the main character, the boss and the only white male member of the IRT.
- Weapon of Choice: Uses a railed SIG-Sauer P226.
- What the Hell, Hero?: He gets called out by his son, Ryan, for pulling him out of his undercover op in Tijuana, Mexico because the bikers can get wind of his FBI status if he doesn't show up sooner than later.
Supervisory Special Agent Clara Seger
- Experienced Protagonist: She's an experienced FBI agent, even before she left the bureau.
- Fair Cop: She's played by Alana de la Garza.
- Omniglot: Clara speaks Thai and apparently other languages.
- It's Personal: In "Type A", there was a cold case that involved the death of one of her friends when she was still working under the UN.
- Married to the Job: So much that Mae tries to get her to socialize with other people.
- Mr. Exposition: She's there to help the team learn what to expect in working in a different country in terms of what to do to avoid any Culture Clash problems.
- Weapon of Choice: Uses a Glock 17. She later switches to a Glock 34.
Special Operations Agent Matthew "Matt" Simmons
- Action Dad: He's the father of two boys and twin girls, and a badass who can take down suspects.
- But Not Too Foreign/Mixed Race: His features and name suggests that he's biracial, given that he's of Asian-American origin.
- "Pretty Like Me" confrims that he's Korean-American. Part of the episode is Matt arriving in Seoul to track down his missing grandmother.
- Experienced Protagonist: He's an experienced FBI agent who use to be with the US Army.
- Fair Cop: He's played by Daniel Henney.
- Omniglot: Can speak Arabic, English, Korean and Spanish.
- Weapon of Choice: Uses a railed SIG-Sauer P226.
Technical Analyst Russ "Monty" Montgomery
- The Face: Since the team is usually in another country, it's also Monty's job to speak with victims' family.
- Mr. Exposition: Helps fill in the team in on information regarding the victims and basic info on a country, sharing this role with Seger.
- Voice with an Internet Connection: Talks like this with the team from FBI HQ since he's not always in the field with them.
- Playful Hacker: Does this when time is running out. Not all jurisdictions like this approach.
Medical Examiner Mae Jarvis
- The Determinator: She won't let rules/cultural barriers hinder her job in examining corpses at all.
- Freeze-Frame Bonus: If you pay attention to closeup of him in the screen, you can see his full name on his badge.
- Omniglot: Speaks English and Thai.
- Hunting the Most Dangerous Game: What he's doing in "The Harmful One", more than just killing.
- Meaningful Name: Means "brave" in Thai.
- Woobie, Destroyer of Worlds: He's the Last of His Kind of his entire family, desperately driven to — in his mind — find worthy sacrifices for their spirits. And in the end, while he's successfully convinced to stop, he's nonetheless Driven to Suicide — all while lamenting that he'll be Dying Alone.
- Dirty Cop: Well, more like a resort dirty security guard. It helps him find victims.
- All of the Other Reindeer: Samraj feel this way since he was in a bad caste, even though it was officially outlawed by the Indian government.
- Tragic Villain: Samraj wanted to ease his father of his pain in the afterlife, but he did it by killing his victims and getting their organs.
Natalie Knox & Nick Jamison
- Freudian Excuse: Natalie was raped as nine year old by her stepfather but no one believed her. Years later, while living in Cuba, she was raped by an American Tourist; that did not do good things to her psyche.
- Love Makes You Evil: Nick
Tuareg Brothers Amajagh, Ben, and Cadi
- Freudian Trio: Amajagh is the Id, Ben is the Ego, and Cadi is the Super Ego.
Abu Hakim Al Badi & Marion Codwell
- Brainwashed and Crazy: Try to brainwash teenage girls into becoming suicide bombers.
- Hoist by Their Own Petard/Too Dumb to Live: They tell one of their victims all about themselves and their operation because they were convinced she'd die for their cause. Instead, she ultimately gives the police everything they need to shut them down.
- Middle Eastern Terrorists: Al Badi is based in Iraq. But it's never mentioned if he was with ISIS or an ISIS-affiliated terrorist group.
- Western Terrorist: Marion is former British MI-6.
- Hikikomori: Is explicitly declared this in his IRT profile, and has the reclusive lifestyle — complete with a Hacker Cave — to back it up.
- Weapon of Choice: Uses an antique World War II-era Nambu Type 14.
- You Killed My Father: Blames his victims for ruining his family and consequently making them get Driven to Suicide.
- From Camouflage to Criminal: After he got discharged from the South African military in the 1990s, he began to target anyone involved in Pretorius, OSS' former black ops unit.
- Wolverine Claws: Uses them to torture and stage his victims post-mortem.
- Would Hit a Girl: Would be willing to hurt females if it needs to be done.