SAN ANTONIO -

Armed with several weapons and hundreds of rounds of ammunition, Miguel Trevino Morales was arrested outside his hometown of Nuevo Laredo without a single shot fired, as a Mexican military helicopter hovered overhead.

Known as “Z-40” or “El Cuarenta,” Trevino was the leader of the Zetas, Mexico’s most dangerous cartel.

Yet when Trevino was paraded before the media, he was free of any shackles or handcuffs.

“I think there’s a lot of factors we don’t know at this time,” said Alonzo Pena, the former ICE deputy director under the George W. Bush administration.

However, Pena said he would not speculate on what those factors might have been.

Pena said Trevino’s arrest would be a “huge blow to organized crime” in Mexico.

“Miguel Trevino and the Zetas had operated with impunity for too long,” Pena said.

Since 2010, the Mexican government has blamed the Zetas for the deaths of 72 migrants who were being smuggled south of Brownsville, a deadly casino fire in Monterrey, and ambush and murder of ICE agent Jaime Zapata in Mexico.

Now that Trevino is custody, Pena said it is too early to predict what effect his arrest may have on the Zetas that have branched out from drug smuggling to human trafficking, extortion, kidnappings, bribery and money laundering.

“There always seems to be somebody willing to come in and fill that vacuum,” Pena said.

Zetas founder Heriberto Lazcano Lazcano was killed last year by Mexican marines, leading to Pena's assumption to power.

Pena said it may take a coup within the Zetas, if there is no transition already in place.

He also said the Sinaloa and Gulf Cartels also could move in on the Zetas territory based in Nuevo Laredo.

Then-president Felipe Calderon had a string of high profile arrests and killings of cartel leaders and major operatives.

Trevino’s arrest is considered a major first for Mexico’s new president Enrique Pena Nieto.

Pena said, “There’s no question there was a lot of pressure by the Calderon administration, but this is certainly a success for the Pena Nieto administration.”

For a list of recent stories Jessie Degollado has done, click here.