Three people have been arrested on drug charges as police investigate the killing of a woman whose body was found in a container on a river sandbar in northern Vermont, according to court papers.

Kayla Wright, 29, of Derby, died of a gunshot wound to the head, Vermont State Police said on Wednesday. Her body was found Tuesday in a truck-bed-style toolbox on a sandbar in the Missisquoi River in Troy, according to an affidavit by a special agent with Homeland Security Investigations.

Bryanna Rooney and Thomas Rooney, of Troy, and another man, Jakiy Tramaine Corey Keith, also known as AB, are facing charges of possessing and conspiring to distribute cocaine base. They made their initial appearance in federal court in Burlington on Thursday. Their lawyers did not immediately respond to emails seeking comment.

Investigators have periodically surveyed the couple’s property as part of a drug conspiracy investigation, according to the affidavit. It recently became the focus of the missing-person investigation of Wright, the agent wrote. No one has been charged in her killing.

Vermont has been grappling with a spike in gun violence in recent years.