Excerpts from nbc5chicago.com:

A fourth person has been charged with murder in the fatal shooting of retired Chicago Fire Department Lieutenant Dwain Williams during an attempted carjacking on Dec. 3rd . The veteran firefighter sustained a gunshot wound and was transported to the hospital where he was pronounced dead.

Jaylen Saulsberry, 19, of Chicago Heights, was charged with one count of first-degree murder and on three warrants.  He was placed into custody at approximately 5:15 p.m. Tuesday night after being extradited from Pennsylvania.

A 20-year-old man, an 18-year-old man and a 15-year-old boy have also been charged in the shooting.

As seen in surveillance video, the suspects jumped back in the vehicle they arrived in as a fourth individual drove the car away.

Police said that it was the past crimes of an alleged carjacking crew around the Chicago area that helped lead to the first arrest.

More can be found HERE, HERE, and HERE.