OAKLAND -- The criminal case against a 16-year-old accused of setting fire to an agender teen's skirt on an AC Transit bus, causing severe burns, will stay in adult court under a judge's ruling Thursday in Alameda County Superior Court.

Oakland High student Richard Thomas faces life in prison with the possibility of parole if convicted as charged with aggravated mayhem and assault likely to cause great bodily injury, felonies that carry a hate crime enhancement alleging that he attacked 18-year-old Oakland resident Luke "Sasha" Fleischman based on Fleischman's gender identity.

Fleischman identifies as "nonbinary" gender, neither male or female.

Authorities say that Fleischman, a senior at Maybeck High School in Berkeley, was sleeping in the rear of an AC Transit bus on Nov. 4 when Thomas set fire to Fleischman's skirt. Fleischman suffered second- and third-degree burns that require massive skin grafting.

In court Thursday, William Du Bois, Thomas' attorney, lost a motion to send the case to juvenile court, which would allow for greater rehabilitation options if he is found guilty. Du Bois challenged the Alameda County District Attorney Office's decision to prosecute Thomas as an adult by arguing that his potential sentence would constitute "cruel and unusual punishment."

But Judge Richard Cousins said that it would be premature to consider potential sentences before a conviction and ordered the case remain in adult court.

After consoling Thomas' tearful relatives outside the courtroom, Du Bois said that he will raise the issue again at the time of Thomas' sentencing, if he's convicted.

Du Bois has said that Thomas was not motivated by homophobia, as has been alleged by police, and has described the incident as "an extremely ill-considered prank that went terribly wrong."

Thomas returns to court Thursday to enter a plea and schedule his preliminary hearing.

Contact Malaika Fraley at 925-234-1684. Follow her at Twitter.com/malaikafraley.