The man, identified as 20-year-old Dmitriy Andreychenko, was arrested for making a terrorist threat, Springfield Police confirmed Friday.
Andreychenko was stopped at the scene by an armed off-duty firefighter until officers arrived and took the man into custody, the Springfield Police Department said.
A video taken by a witness outside the store shows the suspect with his arms up in the air and what looks like an assault rifle slung around his neck as he’s being arrested.
It’s unclear what the Andreychenko's motive was, but police told ABC Springfield affiliate KSPR that the man was recording himself with his cellphone while walking through the store.
Andreychenko had about 100 rounds of ammunition on him when he entered the store, police told the station.
"All we know is the fact that he walked in here heavily armed, with body armor on, and military fatigues on, and caused a great amount of panic inside the store," Springfield Police Department Lt. Mike Lucas said Thursday. "He certainly had the capability and potential to harm people."
"His intent was not to cause comfort or peace to anybody that was in the business here. In fact, he’s lucky to be alive still, to be honest," Lucas added.
In a Facebook post from February, on a page police believe belongs to Dmitriy Andreychenko, he allegedly wrote "It's official. I hate Walmart. Apparently they won't sell Rifle and shotgun ammo if your [sic] under 21. 'New policy' However I can walk into the store with a loaded .40 and nobody says anything. What a joke."
While the name and picture on the Facebook page appear to match the suspect, Springfield Police told ABC News it is too early to officially confirm his ownership of the page.
A spokesperson for Walmart shared a statement with ABC News, calling it "a reckless act designed to scare people, disrupt our business and it put our associates and customers at risk.
"We applaud the quick actions of our associates to evacuate customers from our store, and we’re thankful no one was injured. This person is no longer welcome in our stores. We are working with the authorities however we can and we appreciate their quick response that prevented this situation from escalating further," the spokesperson's statement reads.
"Obviously what’s happened in Texas and Dayton, and that kind of stuff in the last seven days, that’s on everybody’s mind," Lucas said.
Police said there is no longer a threat to the community and the Walmart has since reopened.
Witness Julie Belew said she was getting out of her car at the Walmart when she realized something was going on.
She said she heard someone "say, 'Is that a rifle? Is that a real rifle?' So I looked up and I saw the person to my left was holding a gun."
The incident at the Missouri Walmart comes hours after police in Florida identified a man they were looking for who they alleged told a Walmart salesperson in Port St. Lucie that he was looking for something "that would kill 200 people."
That man was identified as 55-year-old Philip Michael Attey II and during a subsequent interview with detectives, Attey said he is an anti-gun activist and that he believes his statements made to the Walmart clerk in front of a customer "only helps his cause which is for Walmart to stop selling firearms," police said.
Authorities do not consider Attey an immediate threat and he was not arrested or charged. An investigation is ongoing.