A man has been arrested and charged with intentionally lighting the Pacific Palisades Fire in Los Angeles that killed 12 people.
Authorities arrested Jonathan Rinderknecht for allegedly lighting a fire on New Year's Day that burned down much of the Pacific Palisades neighbourhood a week later.
The 29-year-old was arrested in Florida on Tuesday in the US and was set to face court on Wednesday.
The fire was initially put out, but smouldered underground before reigniting during high winds, prosecutors allege.
"The complaint alleges that a single person's recklessness caused one of the worst fires Los Angeles has ever seen, resulting in death and widespread destruction in Pacific Palisades," said Acting US Attorney Bill Essayli.
"While we cannot bring back what victims lost, we hope this criminal case brings some measure of justice to those affected by this horrific tragedy."
AI images seized from suspect's devices
Investigators from the the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), who probed the case, allege that witness statements, video surveillance, mobile phone data, analysis of fire dynamics and patterns at the scene point to Mr Rinderknecht being responsible.
At a press conference, investigators showed AI-generated images, which they allege the suspect created in the weeks before the blaze, showing a cityscape on fire.
Prosecutors said Mr Rinderknecht fled the scene of the original fire, before returning to a trail he had been on earlier to watch it burn and take photos.
It was also alleged that the accused lied about his location on the night in question when under investigation.
Kenny Cooper of the ATF said he could not speak about the motive at this stage.
"I wish we could get into somebody's head, but we can't," he said.
"Evil people do evil things."
In addition to the 12 people killed, the blaze destroyed more than 6,000 homes and buildings in the Pacific Palisades, a wealthy coastal neighbourhood of Los Angeles.
It took firefighters 24 days to extinguish the fire, which was estimated to have caused $150 billion ($228b) in damages.
The finding that the fire was intentionally set could allow the US government to potentially seek the death penalty.
Federal arson charges in the US carry harsh mandatory minimum sentences that range from five to 20 years.
The sentences are even stricter if the arson leads to injury or death, in which case the government can seek up to life in prison or the federal death penalty.
Investigators still have not determined the cause of the Hurst blaze or the Eaton fire, which broke out the same day in the community of Altadena and killed 18 people.
An outside review released in September found that a lack of resources and outdated policies for sending emergency alerts led to delayed evacuation warnings.
The report commissioned by Los Angeles County supervisors said a series of weaknesses, including "outdated policies, inconsistent practices and communications vulnerabilities," hampered the county's response.
ABC/wires
