Javier Escuella was born in Nuevo Paraiso and was once a Mexican revolutionary. According to Agustin Allende, Javier's father was a drunk that worked on his uncle's land.
After spending some time in America, Escuella became a member of Dutch's Gang. When Dutch's gang was disbanded after Dutch went insane, Javier took it hard and returned to Mexico to work as a hitman for Allende, who was a Colonel in the Mexican Army. Marston is forced to pursue him in 1911 by the federal agents.
Prior to John's assault of Fort Mercer, Javier helps Bill Williamson escape into Nuevo Paraiso. Through his association with Colonel Allende, both Javier and Bill pay the local government to protect them from Marston. When John Marston eventually travels into Mexico in pursuit of both of them, Allende takes advantage of this, using Marston to aid him in fighting the rebels led by Abraham Reyes. Eventually, John is betrayed and nearly killed by the Mexican army, therefore he then sides with rebels. Javier is eventually located by Reyes and John in El Presidio during the rebels assault of the fort.
In El Presidio, John holds Javier at gunpoint inside a room within the fort. The two have a conversation with each other. Javier is surprised to see John working for the Bureau of Investigation but John points out that they both now "work for different governments". Javier laughs at this and tries to convince John to let him go. John is quick to remind him of how the gang left him to die and makes it clear to Javier that "It's either you or me. Way I see it, it might as well be you." This doesn't phase Javier and he continues to try to coax a deal out of John. Claiming that he'll give him Bill and even knows the location of Dutch, who is allegedly in Colombia. Javier suddenly pushes a crate onto John, who falls over. Javier then leaps out of a window. John gets up and runs after him. Depending on how the player decides to deal with Escuella. Two outcomes can occur.
Kill Escuella. If the player chooses this, John retrieves Javier's corpse and puts it in a jail cell, because he has to show it to Edgar Ross and Archer Fordham as proof. Before walking out of the jail cell though, John looks at his old friend lying dead on the floor and wipes a tear from his eye and then spits on his corpse. Later on, John takes Javier's dead body to the government agents (Fordham will then say: "I expected him a little more....healthy") and Javier's dead body is taken away.
Capture Escuella. John can capture Escuella by using a lasso to subdue him and then riding back to El Presidios jail. John takes a struggling Escuella to the jail cell, where Javier insults John and tells him that "one day I promise you, you're gonna to regret this." To which John replies "One days about all you got left." The next morning John takes the restrained Javier to the government agents, Javier spits on his arm and calls John a puto (Bitch). He is taken into custody and is not seen for the rest of the game. In optional dialogue, John will share his opinion that Javier will be "locked up for a hell of a longtime unless they choose to hang him." Later in the story, it is mentioned by John that Javier is deceased in a conversation with Abigail.
In "The Gates of El Presidio", if the player captures Escuella, he will ask John "What about your wife and children?". This gives a time frame to Marston's daughter's death, implying that she died after John left the gang.
Hogtying Escuella, sticking him in front of the gate, and then using the Cannon to blow him up will have the same effect as turning him in alive.
Javier calls John his "brother" quite often, implying that they were close friends. Further evidence for this friendship is when John bursts into his hiding place, rather than kill John while he's distracted, he runs out of the window.
Javier has a knife holster, but he does not have a knife. The player can see the knife holster if he kills Escuella. This may be the reason why Javier is inspecting a Knife in Multiplayer.
His sombrero is the same sombrero as the Bandito Outfit's, only that Javier's is a bit bigger while Bandito Outfit is smaller.
His last name "Escuella" is closely related to "school" in Spanish (Escuela). On the other hand, "escollo", which sounds a little alike, has different meanings, like: pitfall, stumbling block, reef, rock, barrier, hidden danger. A mixture of "escuela" and "escollo" could mean that Escuella was really one of the many obstacles Marston has to endure to get his family back.
In the Chuparosa saloon there is a picture on the wall near the table where Banditos can be seen drinking, the man on the picture is possibly Escuella.
Judging from the way Marston and Escuella's confrontation was going, Javier possibly could have talked John out of taking him into custody if he hadn't attacked John and tried to run.
Javier's death is seemingly confirmed in the mission "Old Friends, New Problems" where John tells Abigail "Bill, Javier, Dutch. They're all dead. It don't get more over than that." Despite the fact that John can spare Javier, John still says this line. Meaning that he was indeed executed after being captured by John.
In "The Demon Drink" Allende mentions being somewhat associated with Javier's father by saying "Escuella is from this province. His father was a borracho, a drunk who worked as a laborer on land cultivated by my uncle."
Escuella will be wearing either copper or rusty iron cuffs if the player hogties him.
According to John, Escuella never attempted to teach John or his fellow gang members any Spanish, something Abraham Reyes sneers at.