Chilean authorities arrested 22-year-old volunteer firefighter Francisco Mondaca and former forestry official Franco Pinto over the weekend after prosecutors charged the men with causing massive fires in February that left 137 dead and over 16,000 homeless in central Chile.

Chile declared a state of emergency in February after the appearance of over 100 fires in the central Valparaíso region that caused widespread devastation. President Gabriel Boric described the situation as the worst tragedy in Chile since 2010, when a magnitude-8.8 earthquake and subsequent tsunami left over 500 dead and thousands injured in the South American nation.

While several media reports published at the time attributed the cause of the “wildfires” to a drought and climate change, Chilean authorities launched an extensive and still-ongoing investigation to determine the cause and origin of the deadly fires.

Osvaldo Ossandón, the chief prosecutor in the case, announced on Saturday the arrests of Francisco Mondaca, a 22-year-old volunteer firefighter who stands accused as the material author of the fires, and Franco Pinto, a former member of Chile’s National Forest Corporation (CONAF) who allegedly planned the fires.

Both suspects have been placed under a 180-day pre-emptive arrest while officials continue the investigations and officials have not ruled out that other individuals may have participated in the alleged arson.

Following roughly four months of investigations and evidence-collecting – which includes video surveillance camera footage, cell phone antenna logs, and incendiary devices found in the scene of the fires – Chilean prosecutors were able to determine that Moncada and Pinto had been planning to cause a massive fire for at least four months. 

According to the investigations, Pinto taught Mondaca how to manufacture simple incendiary devices, which the 22-year-old used to generate four incendiary lights — two of which were controlled by local firefighting authorities. The other two managed to cause the deadly fires in Valparaíso.

The prosecution ruled out any psychiatric conditions linked to pyromania in both subjects and pointed to an economic motivation for causing the fires as, according to Moncada, Pinto had told him about a greater financial benefit when there are multiple fires to ensure work.

Chilean newspaper La Tercera reported on Sunday that it had obtained a copy of the testimony provided by Mondaca to Chilean prosecutors after his arrest, which has reportedly been crucial for the prosecution to determine how the deadly fires were started.

In the testimony, Moncada claimed that Pinto, who he described as a “friend,” had allegedly told him on February 2 that the heat and wind weather conditions were “good” to start the fires.

“Therefore, we agreed that I would go in the morning hours of that day to the Las Tablas sector and Camino Viejo a Santiago to set fires by throwing incendiary devices that he had verbally taught me to make in another fire, where Franco [Pinto] told me that I should wrap matches around a cigarette and tie it with a thread,” Mondaca reportedly stated.

Moncada continued by stating that he left his home on February 2 on a vehicle that belonged to his aunt’s deceased husband and that he had been driving since January. Moncada claimed that he drove the vehicle to purchase cigarettes, which he used to craft “incendiary devices” that Pinto had allegedly taught him how to make.

The 22-year-old pointed out that he ended up crafting the incendiary devices inside the vehicle and started to drive through the planned area, throwing the devices along the way using the “technique” taught to him by the former forestry official, who allegedly claimed that the devices should take about ten minutes to start burning.

“I assumed that there might be some lit devices already and I set out to flee the place,” Mondaca reportedly stated, adding that he then toured the places near where he had thrown the devices. After he noticed smoke coming out of one of the areas, he began to drive at “high speed” towards the headquarters of the 13th Valparaíso Fire Company, where he was serving as a volunteer.

Mondaca claimed in his testimony that he did not speak or meet again with Pinto after he threw the devices on February 2, and concluded by stating that he did not use all of the incendiary devices he manufactured on that day and that he had kept the remainder inside a box in his bedroom, which police reportedly later found at the time of his arrest.

The President of Chile’s fireman authority Juan Carlos Field commented on the arrest of the two suspects in an interview on Monday, lamenting the situation on behalf of all roughly 57,600 Chilean firemen. Field asserted that “nothing so horrendous has never occurred” in the organization’s more than 170 years of history.

Field stated that, as a result, the Chilean firefighters organization will seek to raise standards required for volunteers who wish to join the institution, echoing statements issued by Chilean Interior Minister Carolina Tohá, who had previously said that the requirement of a psychological test for would-be volunteers is being evaluated.

Christian K. Caruzo is a Venezuelan writer and documents life under socialism. You can follow him on Twitter here.