A prominent libertarian activist has made controversial comparisons between the late "American Sniper" protagonist Navy SEAL Chris Kyle and mass murderer Adam Lanza, who killed 28 people in a 2012 shooting spree. 

Lanza isn't much different from Kyle, a Navy SEAL sniper who killed 160 people during multiple combat tours in Iraq, Sheldon Richman, vice president of the Future of Freedom Foundation, said on Wednesday. Two years ago, Lanza shot his mother to death, then proceeded to a nearby Sandy Hook Elementary School and killed 20 first-graders and six staffers before committing suicide.

"Excuse me, but I have trouble seeing an essential difference between what Kyle did in Iraq and what Adam Lanza did at Sandy Hook Elementary School. It certainly was not heroism," Richman wrote in an op-ed published on the Future of Freedom Foundation website and reprinted by Reason.com.

"Despite what some people think, hero is not a synonym for competent government-hired killer," he added.

Speaking about the widely debated Clint Eastwood's movie, Richman slammed Kyle's actions, Breitbart reported.

"Let's recall some facts, which perhaps Eastwood thought were too obvious to need mention: Kyle was part of an invasion force: Americans went to Iraq. Iraq did not invade America or attack Americans. Dictator Saddam Hussein never even threatened to attack Americans," he continued. "Contrary to what the George W. Bush administration suggested, Iraq had nothing to do with the attacks on Sept. 11, 2001. Before Americans invaded Iraq, Al Qaeda was not there. Nor was it in Syria, Yemen, and Libya."

"Wars of aggression, let's remember, are illegal under international law. Nazis were executed at Nuremberg for waging wars of aggression."

"The only reason Kyle went to Iraq was that Bush/Cheney & Co. launched a war of aggression against the Iraqi people," he wrote.

The deceased sniper cannot be deemed a hero because the American military personnel's lives that he was protecting  were the aggressors themselves, according to Richman, Newsmax reported.

"What American lives? The lives of American military personnel who invaded another people's country, one that was no threat to them or their fellow Americans back home."

If "an invader kills someone who is trying to resist the invasion, that does not count as heroic self-defense; the invader is the aggressor. If anyone's the hero, it's the latter," he wrote.

The people who Kyle killed on the battlefield only threatened Americans because "American forces waged an unprovoked war against them," he added. "No Iraqi asked to be killed by Kyle, but it sure looks as though Kyle was asking to be killed by an Iraqi. [Instead, another vet did the job.]"