PORTLAND, Ore. (THE OUTLOOK) — A former Gresham High School student was arrested for causing panic at a Walmart in Missouri after walking into the store with several firearms and body armor days after a pair of mass shootings.

Dmitriy N. Andreychenko, 20, faces a second degree charge for making a terrorist threat at the Walmart Neighborhood Market in Springfield, Missouri.

“Missouri protects the right of people to open carry a firearm, but that right does not allow an individual to act in a reckless and criminal manner endangering other citizens,” said Dan Patterson, Greene County Prosecuting Attorney, in a statement.

According to police, Andreychenko walked into the store at 4 p.m. Thursday, Aug. 8, with a tactical rifle, handgun and more than 100 rounds of ammunition. Witnesses said he was pushing a shopping cart and recording a video of himself.

Police were called about a possible active shooter, and the store manager pulled a fire alarm to begin an evacuation.

Eventually Andreychenko was detained by an armed, off-duty firefighter who was at the store, the police statement said. No shots were fired during the incident.

Andreychenko attended Gresham High School during the 2013-14 school year. He then attended the district’s web academy for a portion of the 2014-15 year, Gresham-Barlow School District officials said. He did not graduate from Gresham High.

The arrest occurred days after mass shootings at an El Paso, Texas, Walmart and in a historic district in Dayton, Ohio, which caused the deaths of more than 30 people. Andreychenko said he wanted to see whether the store would respect his Second Amendment rights, according to the probable cause statement.

Patterson compared his actions to shouting fire in a movie theater. Walmart issued a statement praising authorities for stopping the incident from escalating. It also said Andreychenko is no longer welcome in its stores.

Missouri does not require a permit to openly or conceal carry firearms for anyone 19 and older.

Andreychenko could receive up to four years in prison and/or a fine of up to $10,000.

The Gresham Outlook is a KOIN News media partner.