ST. CHARLES COUNTY, Mo. – A teenager faces felony charges nearly half a year after a deadly shooting in St. Charles County, one that followed plans to meet for a marijuana purchase and stage a robbery.

Prosecutors have charged Trevon Gully, 18, with one count of second-degree murder, first-degree attempted robbery and armed criminal action in the investigation.

According to the St. Charles County Prosecuting Attorney’s Office, the Juvenile/Family Court ordered certification on Monday, so Gully will be tried as an adult in court.

Gully and another teenage suspect, Alex Mason, are accused in the death of 15-year-old Lydia Elking on Feb. 18, 2023. They reportedly met Elking in the City of St. Charles before she was fatally shot.

Investigators say there were plans to purchase marijuana, but also pull off a robbery. At somepoint, a struggle ensued, and shots were fired, which struck and killed Elking.

“A seemingly innocuous circumstance can turn deadly so fast that people, especially young people, need to think through their decisions.” said St. Charles County Prosecuting Attorney Joseph G. McCulloch.

Gully is jailed in St. Charles County on a $1 million bond. He will be transferred to general jurisdiction with the purpose of prosecution.