CHICAGO, Ill. (WTVO) — A 16-year-old, 18-year-old and two 19-year-olds have been charged with First Degree Murder in the fatal shooting of a Chicago Police officer.

Chicago Police Department (CPD) Officer Areanah Preston was shot and killed outside of her home on the city’s south side early Saturday morning. The 24-year-old was arriving home from work at the time.

A vigil was held Tuesday night at the Fifth District, where she was stationed.

Preston was set to graduate with a master’s degree in law from Chicago’s Loyola University. She served with the CPD for three years.

“As Officer Preston was returning home from her tour of duty early Saturday morning, four offenders pulled up in a stolen vehicle, the offenders quickly exited the vehicle and ran towards Officer Preston while armed and offender fired at Officer Preston, who returned fire,” said Chicago Police Interim Superintendent Eric Carter. “The offenders continued to shoot at Officer Preston and the offenders stole Officer Preston’s weapon before all offenders fled the scene in the stolen vehicle.”

Her death has been classified as being in the Line of Duty.

The alleged offenders also face other counts, including Armed Robbery.