An 18-year-old Georgia man will spend the rest of his life behind bars for fatally shooting a baby riding in a stroller during a robbery attempt at a seaside town, a judge ruled Thursday.

Johnny Crawford / AP file De'Marquise Elkins appears in court on Aug. 27 during his trial in Marietta, Ga.

De’Marquise Elkins, 18, was sentenced to life in prison without the possibility of parole, The Associated Press reported.

Elkins was 17 at the time of the killing and thus too young to face the death penalty under Georgia law.

A jury last month found Elkins guilty of two counts of felony murder and a count of murder in the March 21 shooting of 13-month-old Antonio Santiago in Brunswick, Ga.

Santiago’s mother, Sherry West, said she was walking home from the post office with her son in the stroller on the morning of the killing. Elkins produced a gun, demanded her purse, then fired a warning shot before shooting West in the leg and the baby between the eyes after she said she had no money, West testified at the trial.

Prosecutors said during the trial that Elkins also had an accomplice, 15-year-old Dominique Lang, who is charged as an adult with murder and will be tried later, despite testifying against his friend at the trial.

Extensive national and local publicity about the brazen killing in the port city of Brunswick, Ga., led to the trial being moved to the Atlanta suburb of Marietta. The sentencing, however, was held back in Brunswick.

Elkin’s mother, Karimah Elkins, was convicted of evidence tampering in the case, and Elkins’ sister was charged with the same offense. Prosecutors said led police to a pond where the .22 caliber handgun used in the shooting was found.

The defense argued unsuccessfully that the investigation was flawed, and that police refused to consider other suspects.

The Associated Press contributed to this report.