SANTA ANA, Calif. – The family of the great-great-granddaughter of Italian education pioneer Maria Montessori expressed relief with the conviction of a car salesman who killed her.

Jonathan Phong Khanh Tran, 22, of Garden Grove, faces a maximum of 55 years to life in prison when he is sentenced May 1 for the murder of Hanna Montessori, as well as the sexual assaults of three other teenage girls working as prostitutes in Orange County.

Tran encountered the 15-year-old Montessori, a former Maine resident who was working as a prostitute in Santa Ana, on Jan. 19, 2004.

Prosecutors alleged Tran, who was convicted Tuesday, was intent on raping Montessori when she jumped out of his truck. She was found in the middle of a residential street, bleeding from the head. She later died from massive brain damage.

“Hanna can finally rest easy, knowing that her murderer is behind bars,” said Phillip Montessori of Portland, Maine, the girl’s father.

The girl’s great-great-grandmother, Maria, founded the Montessori teaching method in Italy a century ago. Used in thousands of schools around the world, it encourages independent learning and promotes the idea that children can teach themselves with little help from adults.

Hanna’s father has said the girl became involved in drugs after he and his wife divorced in 1999 and Hanna was transplanted to Georgia.

She became a ward of the state of Georgia after allegations she was abused at her mother’s suburban Atlanta home, although no one was ever charged. She ran away from several group homes.

She was arrested for loitering in Los Angeles a month before she died but fingerprints taken at the time were not distributed nationally and did not lead to a match with a missing persons report filed when she left Georgia.

It was not until three months after her death that her unclaimed body was identified.

Tran was also convicted of sexually assaulting three other teens who were working as prostitutes in the same area of Santa Ana. In one instance, prosecutors said Tran pretended to be a police officer and ordered the girl to perform oral sex to avoid arrest.

Along with murder, forcible rape and oral copulation under the color of authority, jurors also found sentencing enhancements for being armed with a firearm during sexual offenses.