Updated

The American woman who was jailed for a week after Mexican authorities said they found marijuana under her bus seat says she'll return to Mexico someday, but she'll drive her car.

Yanira Maldonado returned to her suburban Phoenix home Friday, a day after a judge in Nogales, Mexico, dismissed drug smuggling charges.

The judge viewed video that showed the 42-year-old and her husband getting on the bus with just a purse, blankets and bottles of water before it was stopped by Mexican soldiers.

At a news conference near Phoenix Friday evening, Maldonado said she doesn't think she'll end up in jail again when she returns to Mexico. But she says what happened to her could happen to anyone.

She says Mexican authorities should do a better job of getting the people who are smuggling drugs rather than arresting people like her who are innocent.

Alonzo Pena, who retired as deputy director of U.S. Immigration and Customs Enforcement in 2010 and was once stationed in Mexico, said someone else on the bus probably put the drugs under Maldonado's seat without her knowledge and watched her throughout the trip.

The State Department also warns that criminals are increasingly affixing drugs to the bottom of parked cars in Mexico, the removing them after the vehicle enters the U.S.

Those cases are rare, Pena said, because smugglers like to closely watch the drugs crossing the border.

Eric Vos, a lawyer with the U.S. Office of Defender Services who trains federal public defenders, agreed that slipping drugs into unsuspecting travelers' cars or luggage isn't all that common.

"There's just like a million reasons why the blind mule thing is a difficult angle," Vos said Friday.

It's more common, Pena said, for drug carriers to admit they knowingly smuggled because they or their families were threatened if they disobeyed.

Another old smuggling tactic is to advertise work as security guards, housecleaners and cashiers in Mexican newspapers, telling applicants they must drive company cars to the U.S. They aren't told the cars are loaded with drugs.

There were 39 arrests at San Diego's two border crossings tied to the ads for seemingly legitimate jobs between February 2011 and April 2012, according to ICE, prompting the agency to take out ads in Mexican newspapers warning about the scheme.

An Arizona sheriff who has spent more than 40 years along the Mexican border said Maldonado's case probably was a shakedown.

"They've got some good, courageous law enforcement officers in Mexico," said Santa Cruz County Sheriff Tony Estrada. "Coupled with that, you've got really corrupt ones too. And that goes at all levels."

Estrada, whose territory includes Nogales, said finding drugs under the seat of a public bus wouldn't have been enough to arrest her in the U.S.

"Something underneath somebody's seat, anybody could have put it there," he said.

But having Americans on board the bus made it easy for police to either assume the Maldonados were the smugglers, or to target them for a bribe.