CLEARWATER — Pinellas County Sheriff Bob Gualtieri on Tuesday announced plans to strictly enforce a county law mandating background checks for all customers at gun shows, asserting local control in an area that has stubbornly resisted state and federal regulation.

Gualtieri's initiative comes in response to a Tampa Bay Times story last month on the ineffectiveness of local laws closing the so-called gun show loophole. The Times reported that while seven of Florida's most populous counties — including Pinellas and Hillsborough — have ordinances requiring background checks for all sales at gun shows, the laws are largely ignored.

According to Gualtieri, that will no longer be the case in Pinellas County. He said that sheriff's deputies, after extensive consultation with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, plan to monitor upcoming gun shows either in uniform or through undercover operations.

"We're going to make sure the ordinance is enforced," said Gualtieri, a Republican. "The last thing in the world that I want to see, and I hope anyone wants to see, is a firearm fall into the hands of a person who's prohibited by law from possessing one."

The first gun show to be monitored will be held this weekend at the Minnreg Building in Largo. On Monday, Gualtieri sent organizer Guy Lemakos a letter to "remind" him of private vendors' responsibilities under the ordinance.

Lemakos, a licensed St. Petersburg gun dealer, said he plans to personally perform background checks on behalf of the roughly 25 private sellers at the show, which will feature about 120 vendors. He said that he would follow whatever guidelines the Sheriff's Office gives him but that he thinks the ordinance is poorly conceived and unfairly requires gun show organizers to police their vendors.

"I'll do what I have to do, but I'm uncomfortable with it, because I'm not a cop," he said. "It's not the responsibility of a gun show owner to enforce the law."

The ordinance requires that unlicensed firearms sellers — who are not regulated by state or federal law — run background checks on their customers with the help of licensed gun dealers, who have access to a federal database of criminal and mental health records. In Pinellas, violators are subject to a fine up to $500 and up to 60 days in jail.

Mandatory background checks on private firearms sales have long been a goal of gun control advocates. Calls for the checks were revived after the massacre of 20 Connecticut schoolchildren in December. A modified background-check requirement was part of gun legislation that failed to pass in the U.S. Senate last month.

Pinellas County Commission Chairman Ken Welch praised the sheriff's effort, saying he and Gualtieri had discussed how to enforce the gun show ordinance in the days after the Times story was published last month.

"I commend the sheriff for really taking a proactive stance on this once the information came out," Welch said. "It's not a cure-all, but it is addressing a loophole in the law. I think it's just another step to have reasonable laws for gun safety."

In 1998, Florida voters overwhelmingly supported a state constitutional amendment that allowed counties to require background checks for private gun sales on "property to which the public has the right of access."

The language targeted the large gun shows often held at fairgrounds and convention centers. Holders of concealed carry permits were exempted from the background checks.

The vote was influenced by Hank Earl Carr, a Tampa felon who acquired guns despite his criminal record. In 1998, Carr fatally shot a 4-year-old boy, two Tampa police officers and a Florida Highway Patrol trooper before killing himself.

Federally licensed gun dealers who appear at shows must run background checks on buyers. However, the expositions also attract private sellers, who are not regulated under any state or federal law and can sell to customers without checking their criminal histories.

Today, seven Florida counties encompassing close to half the state's population — Pinellas, Hillsborough, Miami-Dade, Broward, Palm Beach, Sarasota and Volusia — have ordinances closing the gun show loophole.

Despite the fanfare that attended the 1998 state constitutional amendment and later passage of the ordinances, the laws have been virtually unenforced, the Times found last month.

As Gualtieri takes steps to alter the status quo in Pinellas, the Hillsborough County Sheriff's Office doesn't have similar plans.

Hillsborough sheriff's Col. Donna Lusczynski said she and other deputies have examined the county ordinance regulating private sales at gun shows and concluded they need further legal guidance. Among the questions, she said, is what constitutes "property to which the public has the right of access."

For example, gun shows are routinely held at the Florida State Fairgrounds in Hillsborough County. However, authorities question whether the law still applies if gun show organizers rent out parts of the property and charge a fee for entrance, thus restricting public access.

She also said the Sheriff's Office, working with limited resources, is emphasizing enforcement of other gun laws, such as those penalizing felons who illegally obtain firearms and the dealers who deliberately sell to them.

"Manpower is limited," Lusczynski said.

Hillsborough County Commissioner Les Miller, a Democrat, said he would be open to discussing funding for the Hillsborough Sheriff's Office devoted specifically to enforcement of the county's background-check law.

Miller approves of Gualtieri's effort in Pinellas. "It's a law that should be enforced," he said.

Peter Jamison can be reached at pjamison@tampabay.com or (727) 445-4157.