(NewsNation) — The Texas woman accused of killing professional cyclist Anna Moriah “Mo” Wilson was arrested in Costa Rica, U.S. Marshals said on Thursday.

Kaitlin Marie Armstrong, 34, was arrested Wednesday at a hostel on Santa Teresa Beach in Provincia de Puntarenas, the Marshals Service said in a statement.

Investigators discovered that Armstrong was using a fraudulent passport when she boarded a United Airlines flight from Newark International Airport and arrived in San Jose, Costa Rica, on May 18.

“The Marshals Service elevated the Kaitlin Armstrong investigation to major case status early in this investigation, which likely played a key role in her capture after a 43-day run,” said U.S. Marshal for the Western District of Texas Susan Pamerleau.

Armstrong is expected to be returned to the United States, where she faces a murder charge.

Wilson, 25, was found dead on May 11 and there have been several twists and turns in the search for her killer, including details of an alleged love triangle that revolved around Kaitlin Armstrong.

Wilson, a competitive gravel and mountain bike racer and Vermont native, had been in Austin for a cycling event. According to an affidavit, Wilson had previously dated Armstrong’s boyfriend, cyclist Colin Strickland, who has cooperated with investigators and is not a suspect.

On May 11, Austin police responded to a 911 call at an east Austin residence where they found an unconscious woman, who later was identified as Wilson, with a gunshot wound. She died from her injuries at the scene, police said.

An arrest warrant revealed that in the hours before Wilson’s death, she went swimming with Strickland. Armstrong and Strickland were dating at the time Wilson was found shot to death, according to an affidavit.

The affidavit further explained that Strickland told police that during a break in his relationship with Armstrong, he met and began dating Wilson.

Investigators said, based on their search of Wilson’s phone, text messages indicated that Wilson thought she “was still in a romantic relationship with Strickland even though he was currently dating Armstrong.”

Armstrong was brought in for questioning in the murder case, but she was released and was on the run for 43 days until her capture.

Authorities said Armstrong sold her vehicle just three days after the alleged crime and boarded a flight from Austin to Houston shortly after being questioned by authorities.

She then flew to New York where she was spotted on surveillance footage before using a fraudulent passport to fly from Newark, New Jersey, to San Jose, Costa Rica, on May 18, the service said.

Police issued a warrant for Armstrong’s arrest on May 17.

Wilson’s family believed she was not seeing anyone romantically. Still, investigators are looking at the case as a crime of passion.

A GoFundMe called the “Moriah ‘Mo’ Wilson Fund” was created by her family saying “Moriah inspired many, lived fully and loved fiercely.”

The Associated Press contributed to this report.