|Death cause:||Shot by Jack Bauer|
|Appears in:||Chaos Theory|
Previously a member of Mara Salvatrucha with the tattoos to prove it, Aguillar worked closely with Zapata during the preparation for his assassination of Federal Reserve chairman Martin Webb in Los Angeles. The night before, Aguillar greeted Zapata upon his arrival at the Staples Center downtown, surprised to see that Zapata had again changed his appearance. Disguised as reporters, the two of them went to the warm-up area beneath the complex to meet Mark Kendall, a mixed martial arts fighter attempting to make his comeback in the Professional Reality Fighting Championship. Zapata offered the fighter a deal: he would pay for his sick daughter's medical care and ensure her survival, if in exchange Kendall agreed to kill a certain person after the match. After giving the shocked and confused Kendall an envelope detailing his assignment, Zapata and Aguillar left, with Aguillar still in shock at his employer's actions.
The two rode the Los Angeles Metro to the Biltmore Hotel, their temporary base of operations, but Zapata changed plans while on the train. Instead, he followed a teenage girl he had seen being harassed by a middle-aged man, both of them just come from the concert at the Staples Center. Zapata intervened and, with Aguillar's help, tortured the man with a stun gun and forced him to admit he had been planning to rape the girl. Eventually, he allowed the man to leave, promising that they would find him again if he hurt anymore women.
At the hotel, Aguillar coordinated the arms deal Zapata was planning with Jemaah Islamiyah, using Alliance Moving as their representatives at the exchange in Playa del Rey. After the deal was interrupted by the LAPD, undercover agent Jack Bauer arrived at the Biltmore along with Vanowen and Emil Ramirez to report the outcome to Vanowen's boss. Aguillar invited Vanowen and Ramirez inside his hotel room and killed them with a single shot to the head each, before attempting to flee. Jack pursued Aguillar into the stairwell and killed him, believing him to actually be Zapata, the target of his undercover mission. After Dan Pascal arrived to bring Jack into custody, he was horrified to realize the dead man was Aguillar and that Zapata was still at large. (Chaos Theory)