Despite the recent murders of American citizens in Mexico and Arizona and a bomb attack against a United States consulate in Mexico, it’s still unclear whether Mexican drug cartels have changed their tactics against U.S. interests, a senior Department of Homeland Security (DHS) official recently said.

“Senator, that inquiry continues but we take that threat very seriously and it would constitute a change in the way in which the cartels have operated with respect with U.S. law enforcement officials or U.S. officials stationed abroad,” said Alan Bersin, the commissioner of Customs and Border Protection, told Sen. Joseph Lieberman (I/D-Conn.), chairman of the Senate Homeland Security and Governmental Affairs Committee. Bersin acknowledged that the there has been significant violence related to organized crime in Mexico. The panel met to review border security along the U.S. border with Mexico.

Sen. John McCain (R-Ariz.) disagreed with Bersin as to whether the cartels have changed their operating methods, citing law enforcement officials from Arizona who say that the “behavior” of drug traffickers has changed significantly in that they are “prone to violence, they are prone to trying to cause accidents on the freeway so they can get away, and they have become much more aggressive. Their weaponry and sophistication of it and types of it has dramatically increased.”

One of those officials, Sheriff Larry Dever of Cochise County in Arizona, testified that burglaries, thefts and home invasions related to drug smuggling are on the rise. Most of the home invasion are occurring by southbound smugglers on their way back to Mexico as they are looking to steal guns, jewelry and cash before crossing the border, he said.

The drug smuggling operations have increasingly become more sophisticated and organized as they look to defend their operations against rival smugglers, Dever said. These organizations will have people perched on a mountaintop with encrypted, radio communications alerting the smugglers to where Border Patrol agents are, he said.

Sometimes the smugglers are “better equipped than we are,” Dever said.

Cooperation among federal, state and local law enforcement officials continues to improve but the lack of interoperable communications equipment among these same officials is still a problem, Dever said. After the body was found of an Arizona rancher who had been murdered on his property, Dever said the pursuit of the shooter was hampered by the inability of these officials to be able to communicate. He added that Border Patrol agents from two different sectors couldn’t event talk to each other.

‘That’s inexcusable and until that problem is resolved all of our law enforcement agents, no matter how well coordinated, are going to have a soft underbelly and the bad guys are going to continue to win,” Dever said.

Dennis Burke, the U.S. Attorney for the District of Arizona, agreed that there has been an overall uptick of violence along the border and that smugglers are more willing to carry firearms. There has also been an increase in the smuggling of weapons and cash from the U.S. into Mexico, he said.

Burke said the Justice Department has been supportive of the need to expand resources related to border security in the Southwest, in particular by increasing the number of prosecutors that work for him.

While DHS continues to review whether to request that the National Guard be used to help monitor the Southwest border, Burke and Dever both said that adding the Guard would bolster border security.

Yesterday’s hearing also examined the status of the virtual fence portion of the Secure Border Initiative, dubbed SBInet. A review of how to proceed with the program initiated by DHS Secretary Janet Napolitano earlier this year is ongoing, he said. Nonetheless, there are elements of the program that could move forward, he added.

“And I would say that while the news regarding the wholesale integration at a border wide level has proven to be beyond the capacity of the contractors and beyond the capacity of CBP to date, there are elements in the Block 1 technology that we would urge this committee and its staff to see whether it actually functions in a way that can be integrated with a placement and deployment of technology across the border so that in fact SBInet technology, if not the SBInet system as originally envisioned, would actually have a place as we move forward,” Bersin said.

Boeing [BA] is the prime contractor for SBInet.