Jack McCauley enjoyed a fast-rising career in the Maryland State Police, starting out on the street and then moving on to gangs, drugs and murders. He went all the way to the top post in the firearms licensing division -- until, he claims, political pressure over the state's high-profile gun control push drove him out.

He was barred from criticizing the policy, he says, and was told from on high that the reason for the sweeping law, which critics say tramples Second Amendment rights, was simple: "It is just votes."

McCauley has since retired over that episode. In an interview with FoxNews.com, he described his frustration and accused Democratic Gov. Martin O'Malley's administration of misleading the public.

"My goal is to educate the public, because the mainstream media and the governor's office are intentionally lying to people," McCauley told FoxNews.com.

The Firearms Safety Act of 2013 -- one of the major gun control laws to pass in the wake of the Newtown, Conn., mass shooting -- bans dozens of assault weapons; earlier this year, it survived a court challenge, which McCauley was involved in. As O'Malley prepares to leave office, and potentially eyes a 2016 White House run, the law stands as one of his signature policies -- even though some gun rights advocates want Republican Larry Hogan, who beat O'Malley's deputy Anthony Brown in an upset election last week, to upend it when he takes office.

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The flashpoint incident for McCauley took place in March 28 of last year. At the time, the O'Malley administration was putting on its full court press to ban numerous types of assault weapons and high-capacity magazines and require special training and fingerprinting to buy a handgun in the wake of the Newtown shooting which took the lives of 20 school children and six adults.

McCauley says, and has sworn in an affidavit in federal court for the unsuccessful suit seeking to invalidate the law, that he was told by the administration not to answer questions from lawmakers about the law's effectiveness in curbing gun crime or stopping mass shootings.

According to his affidavit from this spring's court case, the retired trooper was asked during a State House Judiciary subcommittee hearing, where he was called to testify, if the ban would have an effect on crime in Maryland.

"As I began to respond, I was commanded by Shanetta Paskel, the Deputy Legislative Officer for the Office of Governor Martin O'Malley, not to answer the delegate's question," McCauley said in court papers.

The trooper said he acquiesced to her request because he believed she was his superior in the administration. But, had he been able to answer, he said he would have told the delegate that the banned firearms are almost never used in crimes in the state -- less than 5 percent involve them -- and that it would have no effect on mass shootings since stricter mental health protections were more important.

"Immediately following the end of the meeting ... Ms. Paskel explained why she ordered me not to answer, saying that the act was 'not about policy; it is just [about] votes,'" McCauley's testimony reads.

McCauley's rap on the law is that it amounts to a needless regulation that doesn't do much anyway.

A great many military-style assault weapons indeed are banned by the law. But certain versions of the AR-15, the bugaboo of many anti-gun groups, are still legal to buy and even manufacture in Maryland, often just because the barrel is of a heavier configuration.

Even if he believes it is watered down, McCauley doesn't support the ban. "It's an inconvenience regulation for gun owners," said McCauley. "It's a right, and I believe it's in our Constitution."

He decided to retire after growing disenchanted.

"I'm a police officer who was sworn to uphold the Constitution," McCauley said. "I had no idea how badly we were trampling people's rights."

Gun owners in Maryland largely had been resigned after the law passed, but the issue did re-emerge in the recent gubernatorial election. Hogan had said he would not try to repeal many of the laws that made it through the 2013 legislature, focusing instead on hammering the administration over its heavy taxation policies and the state's anemic economy. But candidates like Steve Waugh, who successfully ran for a state Senate seat, say they already have come up with a plan to repeal the law and hope Hogan will support it. Hogan is only the third Republican governor in the state in half a century.

Supporters, though, have touted the law as critical to reducing gun violence and herald the policy as a model for other states.

"In the post-Newtown era, the state of Maryland has provided a model for common-sense gun violence prevention legislation to take illegal guns off our streets through fingerprint licensing of handgun purchasers, ban military-style assault weapons and limit magazine capacity to 10 rounds," Vincent DeMarco, president of Marylanders To Prevent Gun Violence, said after the law passed in 2013.

Amid speculation about whether the law will come back into the legislative crosshairs, McCauley does not completely fault the O'Malley administration on its crime-fighting strategy. Indeed, he praises it for supporting the creation of warrant squads that have proven effective in getting violent repeat offenders off the street, but says in strategy meetings with administration officials the emphasis was always on gun seizures.

McCauley recalled one instance in which he had to authorize the seizure of 50 guns from a man with no violent crime record but whose alcohol citations while driving labeled him a habitual drunkard, disqualifying him from owning guns in Maryland. By contrast, he recalled an instance when he confiscated just two guns from a pair of murder suspects in Prince George's County who were later sentenced to hefty prison terms on drug charges. Those gun seizures were scrutinized.

"My guys were questioned that month for having only two gun seizures, but just the month before they were praised for the 50 guns seized," McCauley said.

Like traffic tickets or any other crime and infraction stat, it was all about the numbers.

"If my numbers went down, I was in the hot-seat," McCauley said. "Martin O'Malley has done some great things for crime reduction, but this [the assault weapons ban] is not one of them."

Representatives for the O'Malley administration did not return phone calls seeking comment for this article.