Vermont State Police say a Colchester man was charged with possession of and trafficking heroin after a stop on Interstate 89 on Monday night.

On Monday, June 19 just after 11:30 p.m., troopers responded to reports that a man, later identified as 29-year-old Shaun Lacross of St. Albans, was under the influence at a gas station off Exit 4 in Dummerston, according to a VSP press release.

The store clerk told police Lacross displayed a knife while at the checkout counter before leaving the store, the release said. The clerk was able to describe the vehicle in which Lacross left, police said.

Troopers later discovered that car traveling north on I-91 and eventually conducted a traffic stop near mile marker 5 on I-89, according to the release.

After an investigation, troopers said they cited Lacross for possession of heroin, possession of a controlled substance and trafficking heroin.

His passenger, 30-year-old Emanuel Dunn of Colchester, was also charged with possessing and trafficking heroin, according to police.

Both Dunn and Lacross were cited to appear in Vermont Superior Court Windsor Criminal Division on August 15.