In Senator Jeff Sessions of Alabama, opponents of new firearms restrictions have an attorney general nominee ready to implement their frequent call to “enforce the laws on the books.”

During his confirmation hearing on Tuesday, Sessions pledged that, if his nomination is approved, he would take on the rising number of homicides in some American cities by deploying the weight of the federal courts against illegal firearms use.

As proof of his commitment, he cited his own resume.

“As United States Attorney, my office was a national leader in gun prosecutions nearly every year,” Sessions said in his opening remarks.

Available records do not support that statement.

The Justice Department does not maintain comprehensive public records on past prosecution trends. But the Transactional Records Access Clearinghouse, or TRAC, a database at Syracuse University that relies on Freedom of Information Act requests, has collected prosecution records dating to 1986. U.S. Attorneys choose the category that applies to each case, and there is no specific tally of gun prosecutions, which instead are counted under “weapons.”

Sessions served as the U.S. Attorney for the Southern District of Alabama from 1981 until 1993.

According to the TRAC database, between 1986 and 1990, his office did not prosecute a single defendant in what it counted as a weapons case. Many other U.S. Attorney offices also reported no weapons prosecutions during those years, but some reported dozens. In 1986, the Eastern District of Missouri prosecuted 37 weapons cases. In 1990, the Northern District of Illinois recorded 62 weapons prosecutions.

In 1991, Sessions’s office prosecuted 31 weapons cases, placing it 29th, by volume, out of the 93 U.S. Attorney offices nationwide. In 1992 and 1993, Sessions and his team picked up the pace of weapons prosecutions, reporting 49 and 54 such cases, respectively. Those totals nonetheless did not move the Southern District of Alabama out of the middle of the pack.

It’s possible that Sessions was referring during his confirmation testimony to his office’s per capita ranking. By that measure, the low-population district rises in the table, placing in the top five for gun prosecutions per person — but only during those three years of Sessions 12-year tenure.

It was in overall prosecutions that the Southern District of Alabama was a clear national leader under Sessions, with a particular emphasis on drug cases. A report by the left-leaning Brennan Center for Justice argues that Sessions appeared to have “shifted resources toward drug offenses, but away from prosecuting violent crimes.” The report notes that drug cases comprised 40 percent of convictions in Sessions’s district, while such cases made up just 20 percent of the convictions by the two other U.S. Attorney’s offices in Alabama during the same years.

Spokespersons for Sessions and for President-elect Donald Trump’s transition team did not respond to numerous requests to clarify the basis of Sessions’s claim regarding gun prosecutions. Senator Sessions declined to answer a reporter’s question as he left a Senate Republican lunch on Thursday.

The sharp increase in weapons prosecutions in the early 1990s by Sessions’s office and many other U.S. Attorneys around the country appears to have flowed from an initiative known as Project Triggerlock. The effort was spearheaded by Attorney General Richard Thornburgh, who served under President George H.W. Bush, to encourage federal prosecutors to prosecute gang members and drug offenders under federal weapons laws that carried stiff mandatory sentences. Of 31 gun cases Sessions’s office prosecuted in 1991, 29 came through Project Triggerlock.

“I thought it was an effective thing, and we worked hard to prosecute those cases,” Sessions said of the program in a 2005 Senate floor speech.

In his testimony on Tuesday, Sessions described Triggerlock as a predecessor to Project Exile, an effort started during the administration of President George W. Bush that likewise involved using federal gun laws to aggressively punish local criminals. Sessions explicitly recommended resurrecting those policies to reduce homicides in cities like Chicago and Baltimore that have seen sharp increases in shootings.

“Properly enforced, the federal gun laws can reduce crime and violence in our cities and communities,” Sessions told the committee.

Deploying longer sentences as a crime-fighting strategy would mark a reversal of the trend toward de-incarceration embraced in recent years by criminal justice reformers from both parties.

“Just throwing a lot of people in jail is sort of moving back policing to an era that I thought we had moved past,” said David Chipman, a senior policy advisor at Americans for Responsible Solutions and a former ATF official who who investigated gun cases in Texas in the early 1990s.

Chipman said that regardless of whether or not Sessions exaggerated his record as U.S. Attorney, “there is nothing that suggests he will not fully embrace this type of Triggerlock, Exile approach.”

Sessions’s enthusiasm for federal gun prosecutions seems premised on the belief that longer sentences have a strong deterrent effect.

“Criminals are most likely the kind of person that will shoot somebody when they go about their business,” he said during Tuesday’s hearing, “and if those people are not carrying guns because they believe they might go to federal court, be sent to a federal jail, for five years perhaps, they’ll stop carrying those guns during that drug dealing and their other activities that are criminal. Fewer people get killed.”

Emerging criminology research, however, indicates that it’s the swiftness and certainty of punishment, rather than the length or severity, that may have the greater effect on curbing dangerous conduct. And while Project Exile was linked to a drop in killings during the early days of the program, subsequent study has concluded that its violence-reduction powers may have been illusory.

Like many cities, Richmond, Virginia, suffered a spike in violent crime during the 1990s. In 1997, the city became the test site for Project Exile. In the program’s first year, gun-related homicides in the city dropped 40 percent. But researchers now think the number of shootings probably would have fallen without the intervention of federal prosecutors. Other cities with similar populations and crime rates, including Norfolk, Virginia, recorded similar drops in crime rates, without adopting harsher federal penalties for offenders.