Javier Escuella was born in Nuevo Paraíso, Mexico. Javier's father was a drunkard who worked as a laborer on land owned by Agustin Allende's uncle. When he was a boy, Escuella witnessed his uncle and four other men castrated and fed to pigs, because they suggested the villagers demand a fair wage. Eventually, Javier became a notorious bounty hunter and revolutionary, fighting against what he saw as a corrupt system. He ended up killing a powerful, high ranking army officer in Punta Orgullo over a woman he was in love with. Fearing that his loved ones would suffer if he remained in Mexico, Javier fled to America. However, he could not speak any English and ultimately became feeble and starved.

In 1895, while attempting to steal some chickens, Javier came across Dutch van der Linde doing the same. They both laughed, and Dutch fed and clothed Javier, offering him a spot in the Van der Linde gang. Escuella felt an immediate affinity with the gang and its ideals; he came to see the gang as his family and his true home, while especially idolising Dutch as a revolutionary paragon and becoming fiercely loyal to him. Javier functioned as a gunman for the gang, and was involved in a number of robberies and various other crimes across the frontier. One notable example is a bank robbery in Tucson, Arizona, which Javier robbed with fellow gang members Arthur Morgan and Karen Jones.[1] At some point, Escuella heard that his mother had died and that his sister had married. Despite deeply missing them both, he couldn't go back to Mexico because he would most likely be killed if discovered.[2]

Sometime prior to 1899, Javier and Arthur attempted to rob a stagecoach after receiving tips from a crooked lawman in Reno, Nevada. However, they decided to let the stagecoach go when they found out that it was full of women and children. To their disappointment, that stagecoach was robbed by the O'Driscoll Boys the very next day, who had all its passengers murdered.[3]

By 1899, the gang had fled east and ended up in the state of West Elizabeth. They had been camping outside of the town of Blackwater when Dutch caught wind of a boat carrying an immense amount of money. The gang attempted to rob the boat, but the heist went wrong when Pinkerton agents showed up. Javier witnessed Dutch murder a young mother named Heidi McCourt, and participated in the huge gunfight that ensued. The gang subsequently made a desperate escape to the north, ending up in the snowy mountains of Ambarino.