Pablo was arrested along with Henry Mendez and Hugo Moraga while they were in a vehicle on September 8, 2018, as part of an investigation into an attack that occurred in Melipilla in April 2017. The prosecution asked for 36 years and one day for Pablo and Henry for placing, activating, detonating and exploding explosive devices and transporting handmade weapons; possession of firearms, possession and carrying of ammunition. On October 20, 2021 the oral criminal court of Melipilla sentenced Oso to 15 years and 1 day for transporting arms.

In April 2022, the Supreme Court anulled the sentence of Henry and Pablo, so the prosecution will have to find new evidence for a retrial.