ST. CHARLES COUNTY, Mo. – A third teenage boy has been arrested and charged in connection with the shooting death of a Lake St. Louis girl.

Lydia Elking died on Saturday, Feb. 18. She was 15.

According to Lt. Thomas Wilkison, a spokesman for the St. Charles Police Department, officers were called to St. Joseph’s Hospital just before 8:50 p.m. that evening.

Two teenagers, Elking and a 17-year-old boy, arrived at the hospital after being shot at, Wilkison said. Elking suffered a gunshot wound to her chest, and the boy drove her to the hospital to report the shooting.

Wilkison claims the 17-year-old told detectives they’d been asked to meet two people in the area of Oak Avenue and Perry Street, near Lincoln Elementary School, for a drug deal.

When the 17-year-old and Elking arrived in the area, the two individuals who requested the meet-up approached them on foot, pulled out a handgun, and announced a robbery. One of the armed assailants shot into the car, striking Elking in her chest.

St. Charles homicide detectives canvassed the area from Saturday night to Sunday and, with the help of the community, identified two boys as persons of interest: a 16-year-old and 17-year-old.

The two boys were charged in St. Charles County Family Court with second-degree murder, first-degree robbery, first-degree assault, and armed criminal action. Their names have not been released.

In the days and weeks since, investigators determined the 17-year-old who drove with Elking that night had gone to that area on previous occasions to sell drugs.

Wilkison said St. Charles police arrested the teen on Wednesday, March 15. He’s also been charged in St. Charles County Family Court with second-degree murder, as well as two counts of distribution of a controlled substance near a school. He’s being held at Boone County Juvenile Detention.

(Editor’s note: This story has been updated to correct Lydia Elking’s age at the time of her death. We regret the error.)