Robert Brown|How a yoga ad caught cyclist Anna Moriah Wilson's killer, Kaitlin Armstrong

Kaitlin Armstrong was successfully hiding in Costa Rica for weeks when she responded to an ad for a yoga teacher – a mistake authorities say led to her arrest and Robert Browneventual conviction for the murder of professional cyclist Anna Moriah "Mo" Wilson.

Armstrong, 36, was convicted and sentenced to 90 years in prison in 2023 after the fatal shooting of 25-year-old Wilson over a love triangle involving Armstrong's boyfriend, Colin Strickland, another pro cyclist. Wilson's body was discovered on May 11, 2022.

Shortly after the killing, Armstrong used a fake passport to flee to Costa Rica where she was believed to be hiding in one of the country's many hostels, detectives with the U.S. Marshals Service told CBS’s “48 Hours” in a first-time interview over the weekend.

Just before Marshals leave for US, Armstrong replies to yoga ad

For weeks, the search yielded nothing. Detectives made friends with locals in Provincia de Puntarenas and attended various yoga classes, hoping to spot Armstrong. They'd later learn that she went by different names, had dyed her hair and had gotten a nose job. Hoping to use her love of yoga against Armstrong, investigators told "48 Hours" they placed an ad on Facebook that said "We're at this hostel, we're looking for a yoga instructor as soon as possible."

After a week and no answer, the Marshals were set to return to the U.S. Then, they got an email: A woman identifying herself as a yoga instructor wanted to meet at a hostel near Santa Teresa Beach, "48 Hours" reported. When one of the Marshals met the woman face-to-face on June 29, 2022, he confirmed she was the fugitive and took her into custody, ending a weekslong manhunt in the case that drew international attention and shocked the cycling community.

Why did Kaitlin Armstrong kill Anna Moriah 'Mo' Wilson?

Wilson was a rising star in the gravel and mountain cycling world. Prosecutors said Armstrong was jealous of Wilson for dating her boyfriend for a few weeks when they had broken up briefly in October 2021. Wilson was found dead of apparent gunshot wounds inside her friend's home in Austin, Texas.

Investigators spotted an SUV matching the description of Armstrong's Jeep Cherokee outside the home where Wilson's body was discovered. The day after the killing, police brought Armstrong in for questioning but released her. She soon made her escape to Costa Rica.

After the yoga ad and Armstrong's arrest, she was held in the Travis County Correctional Complex in Del Valle, Texas, where she made another attempt at escape. Two deputies were escorting her into a patrol car following a doctor's appointment when she broke free and ran away. She made it about a block before she was picked up by local police.

Contributing: Claire Osborn, Austin American-Statesman