Updated

A 16-year-old Northern California boy has been charged as an adult with assault and aggravated mayhem after police say he set another teen on fire on a public bus.

Alameda County prosecutors charged Richard Thomas, of Oakland, on Thursday in Monday's attack on 18-year-old Luke "Sasha" Fleischman.

District Attorney Nancy O'Malley says her office is charging both offenses as hate crimes, but she did not indicate why.

Oakland police say Fleischman was asleep on an AC Transit bus and wearing a kilt-like skirt when another passenger set the garment ablaze.

The young man's mother and friends say Fleischman identified as "genderqueer," a designation sometimes adopted by individuals who see themselves as neither male nor female.

Thomas didn't enter a plea during his arraignment Thursday. He's due back in court Nov. 12.