Yoga Teacher Accused of Killing Cyclist Mo Wilson May Have Used Sister's Passport to Flee U.S.

Kaitlin Armstrong was arrested in Costa Rica on June 29 after 43 days on the run

Kaitlin Marie Armstrong, Anna Moriah Wilson. Photo: U.S. Department of Justice/Instagram

The Texas yoga teacher accused of killing cyclist Anna Moriah "Mo" Wilson may have used her sister's passport to travel to Costa Rica as she fled the country.

A witness who watched Kaitlin Marie Armstrong's arrest at a hostel on June 29 told Inside Edition that Armstrong, 34, left behind a passport with her sister Christine's name on it.

Authorities previously said she'd used a "fraudulent passport" to fly from Newark International Airport to San Jose, Costa Rica on May 18, the day after a warrant was issued for her arrest.

"She was just asking about how to get around cheaper and then the police came," Zachary Paulsen told the outlet.

Armstrong, who allegedly shot and killed the 25-year-old Wilson in Austin on May 11, was flown back to Texas on Saturday, and her bond will be set at $3.5 million, according to the Houston Chronicle.

Authorities have said that Wilson, a world-class gravel cyclist, briefly dated Armstrong's boyfriend Colin Strickland last fall while the couple was separated. Though Armstrong and Strickland, a professional cyclist, reconciled, he remained friendly with Wilson, and the two went swimming together before the shooting, the Austin American-Statesman reported.

Wilson was in town to compete in Gravel Locos, a 150-mile race through Texas, when she was found "bleeding and unconscious from multiple gunshot wounds" inside a residence, authorities said.

Armstrong was identified as a person of interest in the shooting early in the investigation, and detectives talked to her on May 12 after allegedly recovering surveillance footage that showed her vehicle in the area around the time of the murder.

Deputy U.S. Marshal Brandon Filla reportedly said at a press conference that after she fled the country, authorities attempted to track her by searching local yoga studios in Costa Rica to see if she'd signed up for any classes.

"Once she got to Costa Rica, she didn't really move around a lot," Filla said, according to the Chronicle. "We knew she was going to be associated with some type of yoga studio. When foreign officials arrived at that yoga studio, they did find a handwritten login that was the same alias that she was going by when she traveled to Costa Rica… Once they developed that pattern, it really opened up things and they quickly closed in on Kaitlin Armstrong."

Filla said that Armstrong, who's been charged with one count of homicide and unlawful flight to avoid prosecution, had cut her hair to shoulder length and dyed it dark brown at some point during her 43 days on the run.

She'd been funding her Costa Rica expenses with the $12,200 she pocketed by selling her Jeep in the U.S. before she left, according to Inside Edition.

Wilson had recently moved back to her native Vermont, and left her job as a demand planner for the biking company, Specialized, in order to focus full-time on professional bike racing, according to her obituary.

"We're relieved to know this phase of uncertainty is now behind us and we trust that justice will prevail," her family reportedly said in a statement.