The store where Adam Lanza's mother bought one of the guns used in his school rampage was raided by police Thursday after a theft, a local TV station reports.

According to a report from WFSB-TV in Hartford, Conn., the store where Nancy Lanza bought at least one of the weapons used to kill her and 26 others, Riverview Gun Sales in East Windsor, was raided on Thursday night.

Authorities were at the gunshop when they noticed that not all of its weapons were accounted for, the Hartford Courant reported.

Nancy Lanza's weapons were bought legally and properly registered, but when officials returned to the store to re-examine its business records, they learned that a man had stolen nearly a dozen rifles and shotguns and received a suspended prison sentence with two years probation in May.

A 26-year-old man, Jordan Marsh of South Windsor, pleaded guilty on May 10 to a single count of stealing a firearm and now officials believe he stole an assault weapon on Saturday in an effort to try and pull off a similar attack as the 20-year-old gunman Adam Lanza committed in Newtown, according to WFSB. 

As seen in video footage taken by Eyewitness News, Marsh was shown seen stealing a 50-caliber long gun from Riverview Gun Sales that cost nearly $5,000. 

Marsh also allegedly attempted to take a sniper rifle from the store, police said.

When he was confronted by employees and pulled a knife out on them and then tried to escape from officers on foot before they arrested him.

Marsh was said to be suffering from schizophrenia and it was further reported that he was off his medication on Saturday.

Just a few tender days after the Connecticut school shooting, authorities reported they were getting threats from copy-cats in the area who were threatening to duplicate Lanza’s heinous act.