The driver and all his 25 passengers were killed when the tour bus caught fire and smashed into a barrier on a highway in Taiwan in July.
Taiwanese authorities said they believe Su Ming-cheng poured petrol over the driver’s seat and the floor of the bus near the exit before setting it alight with a lighter.
They had previously said he was drunk.
Local prosecutors said in a statement: “(Su), who was drunk driving, committed suicide by pouring gasoline and setting a fire, killing other passengers.”
An investigation of his phone records in the days before the crash found that his relatives had pleaded with him not to take his own life.
Authorities also said he was a regular drinker with a history of violence.
At the time of his death, he was facing two lawsuits for sexual assault and fighting with a tour guide, both carried out while he was drunk.
“Because of this, Su was depressed,” prosecutors added.
Su was briefly suspended by his employer in May for a different altercation with a tour guide.
The job driving a Chinese group of tourists from China’s northeastern city of Dalian was his first after returning to work.
The crash prompted Chinese authorities to insist that Taiwan improve safety for those visiting from the mainland.
News Source SkyNews