* The Viper. He's an extremely high-profile assassin and MasterOfDisguise who has successfully taken out 12 prominent figures in the world, can quickly dispatch ''anyone'' if he needs to with [[ImprobableAimingSkills incredible sniping skills]], brutally beating people to death in hand-to-hand combat, or just killing them with a simple NeckSnap when their guard is lowered. In short, a ruthless, hardcore, inhuman murderer, and ''completely'' unsympathetic. He's one of the few villains on the show who makes sure AnyoneCanDie. The Viper is foremost concerned about his own safety and assassination jobs. He ''will'' kill whatever impedes the hit, an old nemesis in the form of a British investigator, even his own ''lover''. Worse, he is implied to have [[spoiler: participated in the JFK assassination]]. His target for the 13th kill was ''[[spoiler:The US President]]'' in a very cautious attempt [[spoiler:to snipe him from the luxury box in a football stadium]] while hiding under the bleachers disguised as a security guard after killing one to steal his clothes. [[spoiler:Walker manages to find him and stop the Viper from killing the president because an aide gets in the way and he has to wait to take the shot- long enough for Walker to catch him and knock the high-powered rifle away. They get into a nasty battle, where the Viper produces a trench knife and slashes Walker in the chest. Walker is able to kick him over the edge of the stadium and he smashes into the ground where's he's left critically injured and unable to move. Walker proceeds to ask about his involvement in the JFK murder, suspecting he was involved in it. The Viper warns him he wouldn't even live through next week if the truth was exposed. But then for the sheer hell of it, he ''gleefully'' begins to divulge the ''[[JustBetweenYouAndMe truth]]''- '''BANG!''' The Viper is killed by ''another'' assassin's bullet, and it appears he knew he would [[CyanidePill die anyway]]. Only this one is from a shadow organization that was apparently monitoring the hit. [[TheUnseen We never learn who this was]], and their gunshot echoes through the stadium, leaving Walker unable to pinpoint where it came from. They get away, and the mystery of the JFK assassination is left with an unsettling ending. The shady events behind the killing remain unresolved, with the implications there are incredibly dangerous killers out there who have killed a president before, still seeking to draw blood and send the US spiraling into anarchy.]]
* Every episode with Victor [=LaRue=]. He is genuinely psychotic and a really disgusting bastard with a perverted fascination in Alex. While other [[MonsterOfTheWeek criminals on the show are standard weekly fare]], he takes a flying leap through the MoralEventHorizon and commits especially heinous acts, the worst of these always directed at poor Alex. He attempted to ''rape'' her three times, each one growing even more horrific in magnitude of violence.
** The first time, she was just in the wrong place at the wrong time and got caught in a kidnapping. He then figured out she had a phone on her and was using it to direct Walker and Jimmy to her location. When [=LaRue=] caught wind of the Rangers, he pinned Alex to a wall and tried to rape her the first time. It reduced her to tearful begging. Which was entirely audible over the phone. Walker got so mad, he used his strongest swear in the entire series against [=LaRue=].
---> '''Walker:''' [=LaRue=]! ''LARUE!!'' ''COME TO THE PHONE!!'' '''COME TO THE PHONE, YOU SON OF A''' '''''BITCH!!!'''''
*** Worse, he tried to kill Alex inside a car crusher, by which time Walker intervened and had a direct confrontation with Victor [=LaRue=]. Unfortunately, [=LaRue=]'s military background including combat training, and he was able to fight back, and their struggle caused them to roll into the lever that controlled the car crusher, ''turning it on''. Thankfully, Walker beat [=LaRue=] into submission and stopped the crusher. He and Jimmy got Alex and the other kidnap victims out in time, but Alex was so traumatized she immediately invoked a HoldMe. On top of that, a business she knew and would have worked with turned her off because they dared attempting to ''bail'' him out of jail.
** The second time he appeared, he was put in a psychiatric ward and allowed to leave, through faking sanity, but quickly began plotting revenge on Alex and Walker. When he got the chance, he killed the two cops guarding him under Walker's insistence by committing arson in a motel and ''burning them alive'', then went after Alex again. He cuffed her to Walker's bed after invading his home and then waited for Walker to return, bashing him over the head when his back was turned. When Walker awoke, [=LaRue=] had dragged him out into the scorching heat of the sun, all tied up. He then dumped ''poisonous scorpions'' all over Walker's bare chest. This pissed them off and they stung him, injecting Walker with deadly toxins. All the while, Alex remained bound and gagged while [=LaRue=] tried to rape her to "[[Film/TheShawshankRedemption Marriage of Figaro]]". Walker managed to recover and fight [=LaRue=], but actually ended up on the ''losing side'' because he had been badly poisoned. With luck, he defeated [=LaRue=] again.
** Finally, in his worst killing spree of all, Victor [=LaRue=] played the insanity card at a hearing for his sentence, which Alex attended to make sure he got put away for good. [=LaRue=] deliberately freaked out and sank under the defendant's table just so he could lure a guard down and steal his gun. Alex even screamed for the guard not to go under the table because she alone knew what [=LaRue=] was capable of. Too late. [=LaRue=] disarmed the bailiff and killed him with his own gun, then shot down the other guards in the courtroom and took everyone hostage, enacting his own hellish KangarooCourt for the rest of the episode, screaming for Walker to show up so he could rape and murder Alex in front of him. However, Walker was off chasing down some other crooks at the time this happened and he would have to come all the way back to Dallas, giving [=LaRue=] plenty of time to start a bloodbath in the wake of what would definitely be a death sentence. Now, [=LaRue=] knew he was a dead man in the making and decided to take as many people down with him, or worse, demean them with insane demands at the risk of being shot. He did all of the following:
*** Killed seven people in total, starting with the bailiff by stealing his gun and shooting him in the chest with it.
*** Next, he offed the courtroom guards before they could react to him taking the bailiff's weapon.
*** Brutally executed his attorney for turning against him once he realized [=LaRue=] was really an unforgivably rotten maniac. The bailiff flees for his life, but cannot outrun the deadly bullet.
*** Barricades the courtroom shut and holds everyone hostage until Walker returns, taunting Trivette and C.D. relentlessly.
*** He demanded and bitched over a ''[[ArsonMurderAndJaywalking sandwich]]'' of all things.
*** Eventually took out the well-meaning judge that saw through his facade, killing her because she angered him with the promise that he would be brought to justice.
*** Manipulated another hardened criminal awaiting his own trial into working with him, whom he then shot to death when the crook got cold feet in the wake of [=LaRue=]'s actions, because what he was doing was ''far'' more cruel and demented than he could stomach.
*** He also got enraged at a couple awaiting a divorce hearing. He poured his wrath out on the couple for splitting up and letting their young daughter's life be torn apart, so he wanted her to have retribution and decided that since a little girl's mommy and daddy hated each other, the girl should decide which one she wanted to live, while the other would be punished for the divorce by being killed. The family was fortunate enough to be spared. Ironically, this saved the marriage, mainly because of the trauma he caused.
*** Ordered Alex to shame herself by exposing her chest, at gunpoint. She remembered every terrible instance [=LaRue=] tortured her through disturbing flash backs to painful memories. But this was the straw that broke the camel's back.
** After making Walker and Alex go through hell three times in a row, Walker shows up with a small army of law enforcement officers to take back the courtroom by force. [=LaRue=] is thrown off balance by his sudden and forceful arrival, and becomes conflicted about whether or not he should aim his gun at Alex or Walker. He chooses Walker. Walker could choose to fight him. Not this time. That bastard has finally crossed the line and receives no more chances. Walker ''[[KarmicDeath kills]]'' ''[[AssholeVictim Victor [=LaRue=]]]'' ''[[CrowningMomentOfAwesome stone dead]]''. He [[DiesWideShut dies with his eyes blank and totally open]] in a terrifying literal DeathGlare.
** But this is still not enough for Alex to think Victor [=LaRue=]'s gone for good. She is so freaked out from these events that when she sees the stretcher being taken away with [=LaRue=]'s cadaver covered up by sheets, he haunts her memories. Suddenly, [=LaRue=] ''[[JumpScare pops up from underneath the sheets]]'' with a ScareChord and gives her the same dead stare that he had when he was killed. Alex snaps out of this scary trance. AllJustADream... OrWasItADream The scene is made worse by the SoundtrackDissonance which actually continues into the credits and reflects the lingering impact of Victor [=LaRue=]'s perversions that have no doubt left their mark on Alex.
--> ''See you in my dreams''
--> ''(You're all I need)''
--> ''Now relive the memories''
--> ''(Sweet memories)''
--> ''Of you and me''
--> ''(It's you and me forever)''
--> ''And if tomorrow never comes...''