The man gunned down execution-style at the Southlake Town Square Wednesday was an attorney linked to a major Mexican drug cartel who had been living in Southlake with his wife and three children, NBC 5 has learned.

The victim was identified as Juan Jesus Guerrero-Chapa, 43, of Guanajuato, Mexico.

Guerrero has been named in various Mexican news reports as a lawyer for the Gulf Cartel, one of the largest and most violent drug organizations in Mexico.

According to the respected Mexican investigative magazine Proceso, Guerrero was arrested on drug charges by the Mexican military on Feb. 26, 2002, and taken to the maximum-security prison known as La Palma.

At the time, Guerrero was representing a top leader of the Gulf Cartel. The attorney was soon freed because of an apparent lack of evidence, Proceso reported.

Guerrero lived in Southlake with his family, who are now in hiding under police guard after a masked gunman jumped out of a white SUV, opened fire, and shot Guerrero multiple times at about 7 p.m. Wednesday, police said.

Guerrero was in the passenger’s seat of a 2012 Range Rover. His wife, who was behind the wheel at the time, was unhurt, police said.

The gunman returned to the white SUV, driven by a second man. They fled down Southlake Boulevard, police said.

During a news conference Thursday, Southlake police released surveillance photos of an SUV they believe to be the getaway vehicle and said the Texas license plate contains a "B" and a "Y." Those photos are inset in the image above.

The victim’s car is registered to Armando Guerrero-Chapa with a post office box in Plano.

State records show that in December 2010, Armando Guerrero and Juan Guerrero formed a gambling company called Siglo 21, based in a small town along the border near McAllen.

Police have been unable to locate Armando Guerrero, Southlake police chief Steve Mylett said.

A webpage that appears to be Juan Guerrero’s LinkedIn profile says he is a rancher in Guanajuato and raises a “wide range of livestock and farm animals.”

“Juan Jesus Guerrero Chapa enjoys the regional flavors of the restaurants in his hometown, and he often donates cows and calves to be prepared by Mexican chefs,” the profile said.

The page also identified him as the owner of Elite Charolaise Mexico and gives his hometown as McAllen.

In a trial earlier this month of a reputed Gulf Cartel leader, Aurelio Cano Flores, the U.S. Justice Department said the organization distributed more than 1.4 million kilograms of cocaine and 8,000 metric tons of marijuana into the United States from 2000 to 2010.

Witnesses testified in the trial that in those 10 years, the Gulf Cartel grew from an organization of only 100 members controlling three border towns to an organization of 25,000 people controlling the drug trade in over half of Mexico.

Southlake police are asking anyone who either witnessed the shooting or has information about the shooting to please contact Det. Carl Moore at 817-748-8127.