Days after 18 people were killed in Lewiston, Maine, an 18-year-old man was arrested in a town less than 80 miles away after authorities reported finding a photo online of him armed in a Walmart parking lot threatening another mass shooting.

The photograph, which was shared on the social media platform SnapChat, showed the teenager armed with a firearm and ammunition, multiple outlets reported. The photo, which the Somerset County Sheriff's Office told media was taken in a Walmart parking lot in the small Maine town of Palmyra, included the caption "Lewiston Part 2."

Fatal shooting in Georgia:Former college professor gets life sentence for fatally shooting 18-year-old student

Palmyra located 80 miles from Lewiston

Palmyra is located less than 80 miles northeast of Lewiston, the site of this year's deadliest mass killing so far in the United States.

Authorities had identified Robert Card, a man with military training, as the suspected lone gunman who killed 18 people and injured 13 others last Wednesday in two shootings - one at a bowling alley and another at a bar. Card, 40, was found dead Friday of an apparent self-inflicted gunshot wound.

The suspect in Palmyra was arrested Sunday after the sheriff's office said it was notified of the teenager's threatening post, according to multiple outlets citing a media release from the agency.

USA TODAY has requested a copy of the media release.

Maine shooting:Timeline of the deadly mass shooting

Sheriff's deputies seize rifle

The individual was identified in media reports as 18-year-old Michael Bowden, a resident of Etna in the neighboring county of Penobscot.

Bowden had been terminated in 2021 from his employment at Walmart, but investigators determined that he had recently been seen in the store's parking lot "on a nightly basis," media reported, citing the media release.

Mass killings in the U.S.:Rampage in Maine is the 36th mass killing this year

After taking the photo referencing the Lewiston shooting, Bowden sent it to an employee at the Walmart, Somerset County sheriff’s Chief Deputy Mike Mitchell told centralmaine.com.

“They were communicating back and forth through Snapchat messaging, and (the employee) basically said, ‘What is this?’ ” Mitchell told the outlet. “We take this stuff very serious. You have to nowadays."

Bowden was arrested at his home and charged with aggravated reckless conduct and domestic violence terrorizing, according to reports. Investigators also seized a bolt action hunting rifle suspected of being the firearm seen in Bowden's Snapchat post.

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]