San Mateo woman's family fighting for safe return after Mexican abduction

San Mateo resident Monica De Leon Barba has been held against her will for more than 120 days in Mexico by kidnappers demanding a ransom from her family.

Her abductors have sent the family evidence that Barba is still alive. But four months after she was snatched off the streets in a town outside Guadalajara, the 29-year-old remains missing.

"For my mother, my father, and myself, it's been absolute torture," Barba’s brother, Gustavo De Leon, said in an interview with KTVU on Friday.

The FBI on Thursday offered a $40,000 reward for information leading to Barba’s safe return, spurring new interest in the case that the victim’s friends and family have been pushing to keep in public view.

They started the Facebook group called Help Find Monica spreading the word about her abduction.

Barba’s brother described his sister being thrown into a van in the town of Tepatitlan, around 5 p.m. on Nov. 29.

He said the family has been in contact with her abductors, who are demanding an undisclosed ransom.

The family reported her disappearance to the U.S. State Department and spoke with Rep. Jackie Speier and Sen. Alex Padilla.

But Gustavo said his sister’s case has not gotten the attention other kidnapped Americans have received and he wants local and Mexican authorities to do more.

"In my sister's case, it's been four months and we haven't had that kind of rally, or action by the judicial or political system that I can see," he said.

He noted that when four Americans were kidnapped in the city of Matamoros near the Texas border earlier in March, their case received widespread attention.

But kidnapping for ransom cases in foreign countries can be tricky, and often difficult to resolve, experts say.

"It’s not like the government in Mexico can always help," said Rick Smith, a retired FBI agent in San Francisco. "It’s done by a gang or cartel and she’s targeted and they hold all the cards."

Smith, who now operates a private investigation firm and is not involved in the case, said complying with ransom demands doesn’t guarantee a loved one’s safe return.

"The FBI does not endorse the family paying because it just emboldens these people and sometimes they don’t get the person back," he said. "But that’s easy to say when you’re not involved."

Barba’s family, meanwhile, is working hard to raise awareness and hopes to get her back home safe soon.

"We miss her terribly and there's no one, less deserving of this terrible fate right now," he said.

Anyone with information about the case can contact the FBI at 1-800-call-FBI or leave a tip online at tips.fbi.gov.

Evan Sernoffsky is an investigative reporter for KTVU. Email Evan at  evan.sernoffsky@fox.com and follow him on Twitter @EvanSernoffsky