(CNN) -- A man accused of walking into a Walmart in Missouri equipped with body armor, a handgun and a rifle less than a week after a gunman killed 22 people in a Texas Walmart said it was a "social experiment" and not intended to cause panic, police say.
"I wanted to know if that Walmart honored the Second Amendment," Dmitriy Andreychenko told investigators, according to a probable cause statement filed by Springfield police.
Andreychenko, 20, was arrested Thursday after panic ensued when he walked into the store that afternoon with his rifle slung across his chest, pushing a shopping cart and recording himself with a cell phone, police say.
Patrons fled the store, police were called, and an off-duty firefighter detained Andreychenko until officers arrived to take him into custody, police said.
He told investigators he intended to buy grocery bags, and didn't intend for any negative reaction, police said.
And he claimed the recording was in case anyone stopped him and asked him to leave, police said. His wife and sister told him beforehand that the idea was not smart, especially considering the recent shootings in El Paso and Dayton, according to the document.
He told his sister it was "a social experiment on how his Second Amendment right would be respected in a public area," police said, citing an interview with the sister. The rifle he carried had a loaded magazine, but a round was not chambered; and the handgun was loaded with a round in the chamber, the probable cause document said.
'He's lucky to be alive'
He faces a charge of making a terrorist threat in the second degree, the police department said on Twitter.
CNN was unable to determine whether he was represented by an attorney. The consequences he faces are not a reflection of how Missouri -- an open carry state -- respects the Second Amendment, prosecuting attorney Dan Patterson said in a statement.
"Missouri protects the right to open carry a firearm, but that right does not allow an individual to act in a reckless and criminal manner, endangering other citizens," Patterson said. "As Justice Oliver Wendell Holmes famously explained, 'The most stringent protection of free speech would not protect a man ... falsely shouting fire in a theater, causing a panic.'"
Police Lt. Mike Lucas said he did indeed cause a panic.
"His intent was not to cause peace or comfort to anybody that was in the business," Lucas said. "In fact, he's lucky to be alive still, to be honest."
No shots fired
Andreychenko entered the Walmart Neighborhood Market on Thursday afternoon, Lucas said.
When he did, the store's manager pulled the fire alarm to initiate patrons' escape, according to CNN affiliate KYTV.
No shots were fired, and no one was injured, police said. Lucas said the recent spate of mass shootings in public places may have placed customers on heightened alert, leading them to call police to report an active shooter.
"All we know is the fact that he walked in here heavily armed with body armor on, in military fatigues and caused a great amount of panic inside the store. So, he certainly had the capability [and] the potential to harm people," Lucas said. "And then obviously what's happened in Texas and Dayton and all that kind of stuff in the last seven days -- that's on everybody's mind."