HOUSTON—A Baytown teenager could face up to 20 years behind bars after taking responsibility for a joyride crash that led to the deaths of his brother and three friends.

Bobby Davis, 16, said on Tuesday that he crashed a stolen sport utility vehicle into a parked train, the Houston Chronicle reported in Wednesday’s online edition.

His admission that the allegations against him were “true” is the juvenile court equivalent of a no-contest plea. It came after prosecutors reduced charges against him from four counts of felony murder to four counts of manslaughter, District Attorney’s Office spokeswoman Donna Hawkins told the Chronicle.

State District Judge Michael Schneider last year rejected Harris County prosecutors’ request to certify Davis, then 15, to be tried as an adult. Davis was accused of stealing a neighbor’s Jeep Cherokee and taking the younger teens on a joyride. The vehicle slammed into the side of a train parked at a rural railroad crossing outside Baytown on July 14, 2007. The impact killed his younger brother, Austin Davis, 14, and three girls: Loral Moyers, 12; her cousin, Macy Moyers, 14; and Colette Windham, 14.

The railroad crossing had no street lights, flashing lights or crossing arms, and the tanker car that Davis struck had no reflective material to help make it visible at night. The train had been blocking the crossing for 33 minutes when the wreck occurred.