The recent string of arrests tied to the Los Angeles fires has brought a puzzling question back into focus: Why do people intentionally set fires? The answer, it turns out, is far from straightforward.

Experts say there’s no one-size-fits-all profile for arsonists. “It’s a very odd crime that just a few people understand,” explained a former LA County arson investigator who spent decades studying the phenomenon. From financial gain to mental health struggles, the reasons behind arson are as varied as the individuals committing it.

For some, fire is a tool—like the person who burns their car for insurance money or the business owner who sets their office ablaze to destroy records. These “one-and-done” cases are often driven by practical motives. But outside of these deliberate acts, there's a whole other world of fire-setting behavior.

Urban fires, like those set in dumpsters or alleys, happen daily in big cities. While they often fly under the radar, they can still cause significant damage. In some cases, these fires are linked to mental health challenges. For example, those experiencing homelessness may accidentally start fires while trying to cook or stay warm. Others, battling severe mental illness or addiction, might set fires as a result of psychosis or other issues.

Then there’s the most dangerous group: serial wildland arsonists. These individuals, though rare, have the potential to cause catastrophic damage. “A true wildland serial arsonist has the power of an atomic bomb at their fingertips,” said the former investigator. Surprisingly, firefighters make up a notable percentage of this group—about a third. For some, it’s about the thrill or the chance to play the hero.

Climate change adds another layer of risk. While arsonists aren’t necessarily more active in extreme weather, the conditions created by a warming planet can turn small fires into massive disasters. A fire set during a heatwave, for instance, can quickly spiral out of control, as seen in California’s Park Fire, one of the state’s largest on record.

Understanding the psychology behind arson is crucial to preventing it. As experts continue to study this complex crime, one thing is clear: the reasons people set fires are as unpredictable as fire itself.