Prosecutors have dismissed all charges against a Vadnais Heights man whose son allegedly threatened to shoot up his school after the Parkland, Fla., school killings.

Attorney Bruce Rivers said he learned Thursday that the Ramsey County Attorney’s Office dropped the case against his client, Christopher Stowe, after lab results showed that authorities had misidentified a gun taken from his home as a fully automatic weapon.

“It was a classic case of government overreach,” Rivers said. “They filed charges without having the evidence to prove the elements of the crime.”

The case against Stowe, his wife, Lisa Stowe, and the couple’s then-13-year-old son — who were all arrested and charged in early March — focused public attention on how police and schools deal with alleged threats.

The boy, who family members have said is autistic, had allegedly threatened to shoot classmates at the Academy for Sciences & Agriculture High School in Maplewood just weeks after 17 people were killed on Feb. 14 at Marjory Stoneman Douglas High School in Florida.

The County Attorney’s Office filed notice Wednesday that the case was being dismissed because one gun found in the family’s home was a semi-automatic weapon and not a fully automatic weapon.

“After further investigation requested by the prosecution, the Ramsey County Attorney’s Office determined that the evidence did not support any felony level charges against Christopher Stowe,” county attorney spokesman Dennis Gerhardstein said in a written statement.

Stowe had been charged with two felony counts of prohibited possession of machine guns and short-barreled shotguns and one count of gross misdemeanor negligent storage of firearms where a child can access them.

One felony count was dismissed in May when authorities learned that a different gun had been wrongly identified as a short-barreled shotgun.

Stowe, 41, felt “vindicated and victimized,” Rivers said.

“He was relieved,” Rivers said. “It’s been a very traumatic experience for this family.”

The Ramsey County Sheriff’s Office said in early March that they had seized dozens of firearms, thousands of rounds of ammunition and at least one explosive device from the Stowe home.

Chief Deputy Steve Frazer said federal authorities are reviewing Christopher Stowe’s case for possible charges, he said. If federal charges are not filed, the sheriff’s office would likely ask the Vadnais Heights city attorney to consider lower-level counts.

“This is just another twist in the path,” Frazer said. “It’s far from over.”

Frazer said the sheriff’s office investigated appropriately and acted on information from the Bureau of Alcohol, Tobacco, Firearms and Explosives in identifying the guns in question.

One gun was short-barreled, but it turned out to be a rifle and not a shotgun, which didn’t fit the state’s case or purview, he said. Federal authorities can pursue charges on short-barreled rifles, he added.

Frazer said distinguishing between semiautomatic and fully automatic weapons isn’t always easy.

“I can’t say enough good things about the way the case was handled,” Frazer said. “The system worked the way it was supposed to work.”

The Vadnais Heights City Attorney’s Office has charged Lisa Stowe with a gross misdemeanor. Assistant City Attorney Mark Gaughan said he expected Christopher Stowe’s case to “come through my office for review at some point in the near future.”

Rivers said Christopher Stowe would not comment on the dismissal. The son’s status is unclear; many juvenile proceedings are not public.

“This is a good day for the Stowe family,” said Samuel Surface, the attorney for Lisa Stowe. “[The sheriff’s office] has publicly shamed this family enough.”