Detectives used an ad for a yoga teacher to finally find Kaitlin Armstrong after she’d stolen her sister’s passport to flee to Costa Rica, cut and dyed her hair, and even gotten plastic surgery to disguise her appearance.

US Marshals on the hunt for Armstrong after the shooting death of pro-cyclist Moriah “Mo” Wilson were on the verge of leaving Costa Rica after tracking Armstrong to a tiny village way off the beaten path, where it “seemed like she was trying to establish roots,” according to an American restaurant owner in Santa Teresa.

She used the name “Ari” to Greg Haber, he told CBS News’ “48 Hours,” although she’d also used the name “Beth” to others. And her new brown hair and altered nose made her look like any other American woman tourist in the beach town.

A woman operative the marshals had sent in to various yoga classes to try to suss Armstrong out told them the alterations to her appearance likely would have fooled her.

“She told me, I think if I would’ve run into her at the yoga studio doing yoga classes, I don’t think I would’ve recognized her,” Deputy U.S. Marshal Damien Fernandez said.

But the ad on a Facebook page drew her out. Fernandez and his partner, Deputy US Marshal Emir Perez, were already back in San Jose, Costa Rica’s capital, when Armstrong answered the ad. They rushed back to Santa Teresa. Perez went into the restaurant to meet her. It took a few minutes, but, he said, her eyes gave her away.

“The eyes are the exact same ones that I saw in the picture,” he said. “And this is her 100 percent.”

“He gets in the car, and he is like, ‘That’s her. She’s in there,'” Hernandez said.

Costa Rican authorities made the arrest. Armstrong was brought back to Texas for trial and was convicted and sentenced to 90 years in prison.

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[Featured image: Kaitlin Armstrong, before and after fleeing the country/police handouts]