The drug cartel violence has seemingly quieted down in Tijuana and Baja, as reports of murders and mayhem have gone off the front pages.

But in what seems to be a contradiction, 2010 was the worst yet in the Mexican drug wars, with 15,000 people murdered.

The 10News I-Team learned a dramatic shift in the war has led to some changes.

A former U.S. intelligence officer told 10News a winner has been declared in Baja and Tijuana drug wars

"The Sinaloa Cartel has pretty much won this area," the officer said.

The officer said the Sinaloa Cartel and others have come to the realization that, as American organized crime figured out years ago, bad publicity is bad for business.

The officer made clear that the cartels have not reformed; they simply have reduced the high-profile elements of their crimes. Instead of murders and beheadings in public, cartel business is quietly handled in more private places.

Another dramatic change for the cartels is a shift in their business strategy. The officer said cartels have seen there is money to be made not just in transporting drugs into the U.S., but in selling drugs to the growing Mexican middle class.

"They weren't selling drugs in their own cities to their own people, now they are," said the officer.

According to the officer, regions, cities and towns are being divided up. Agreements are made to respect other cartels' turf.

In the case of Tijuana, it's the Sinaloa Cartel that controls the trafficking in and through the city.

Not all areas of Mexico have one cartel in complete control, which is why there are still news reports about the violence in other areas of the country.

For example, a casino in Monterey was recently torched. Authorities said 53 customers trapped inside died.

Recent stories out of that area reported five members of the Zetas Cartel were responsible. The Zetas Cartel is not one of the cartels who want to stay low-profile. The intelligence officer told 10News the "Zetas are screwing up the plan for everybody".

According to the officer, the Zetas are very much in pitched battles with several groups in an attempt to extend their control.

The officer said the gang was formed from Mexican special forces personnel hired as enforcers. They eventually set up their own organization and remain unwilling or unable to form alliances with other cartels.