The Mall of America now is using metal detectors at one of its entrances on a trial basis, a move taken after two incidents of gunfire within the past year and nearly eight weeks after a man with a rifle allegedly robbed two retailers and forced a lockdown of the massive shopping and entertainment complex.

Bloomington police were notified of the mall's security enhancement about a week ago, Deputy Police Chief Michael Utecht said Tuesday.

In response to a Star Tribune inquiry about the installation of the metal detectors along with patrons having their bags searched before entry, mall spokeswoman Laura Utecht also clarified that the metal detectors are in use only at the north entrance on Lindau Lane.

"At Mall of America, the safety and security of our guests, tenants and team members is our top priority," she said in a statement. "We are always looking for innovative ways to enhance security using the latest technology.

"With Mall of America being such a unique property, it is important to thoroughly evaluate this technology onsite to ensure its accuracy, effectiveness and efficiency. We are currently in the process of testing a variety of options that may allow us to further enhance our advanced security systems at Mall of America."

The spokeswoman said the trial "is taking place over the next month at the north doors, but the location might change as we go through the testing. … Anyone entering the north doors will need to go through the detector.

Laura Utecht declined to reveal what patrons should avoid trying to carry through the metal detectors or what enforcement actions, if any, would be taken based on what the detectors flag. She did not say why the north doors were chosen as the only location for the detectors.

She also declined to say whether people who work at the mall are required to go through the detectors.

There has long been a policy banning guns and fireworks at the Bloomington mall, which has hosted millions of visitors annually since it opened 30 years ago but has never had metal detectors or bag searches in all that time.

Gun-rights advocates have long contended that the mall, as a landlord, lacks the authority to ban permit-to-carry holders from bringing firearms into the complex's common areas. Individual stores do have that right.

State law "prevents landlords from restricting lawful carry," said Rob Doar, senior vice president of the Minnesota Gun Owners Caucus.

Should the metal detectors keep gun-possessing permit-to-carry holders out of the mall, "it will pose an interesting legal issue," Doar said.

On Aug. 26, Cartier T. Alexander, 29, of Woodbury allegedly robbed two Mall of America stores shortly after pulling off the same crime at a Minneapolis pawnshop. Alexander stands charged with first-degree aggravated robbery in connection with targeting a Lids sports apparel shop and a kiosk retailer as well as Twin Cities Pawn on E. Lake Street in Minneapolis.

Mall security apprehended Alexander and seized a loaded rifle from him, according to the charges and other court documents.

About three weeks earlier, gunfire erupted inside the crowded mall. Shamar Alon Lark, 21, of Minneapolis and Rashad Jamal May, 23, of Burnsville are charged with second-degree assault and felony discharge of a dangerous weapon. They remained jailed Friday in Cook County, Ill.

The two were shown in mall surveillance video fleeing a fight among four other individuals that led to Lark allegedly firing several shots. No one was injured in the incident that sent shoppers scurrying and led the mall into lockdown.

On Dec. 31, two people were shot and wounded following a dispute on the mall's third floor. Kahlil M. Wiley, 19, pleaded guilty to second-degree assault in connection with that shooting and received a 3 ¾-year sentence, with the first two-thirds in prison and the balance on supervised release.