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Fugitive Texas murder suspect Kaitlin Armstrong has been captured in Costa Rica, more than six weeks after Austin police obtained a murder warrant in the death of pro cyclist Anna Moriah "Mo" Wilson.

U.S. Marshals announced the bust Thursday morning, 43 days into the manhunt, and said she had been captured Wednesday.

Costa Rican authorities assisted U.S. law enforcement in tracking Armstrong to a hostel on Santa Teresa Beach in Provincia de Puntarenas, the Marshals announced. Authorities said she used a "fraudulent passport" to fly from Newark, New Jersey, to 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. "This is an example of combining the resources of local, state, federal and international authorities to apprehend a violent fugitive, bring an end to that run and hopefully a sense of closure to the victim’s family." 

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Moriah Wilson and Kaitlin Armstrong

Left: victim Moriah "Mo" Wilson after a race. Right: A photo of suspect Kaitlin Armstrong released by the US Marshals. (The Wilson Family/US Marshals)

Armstrong is expected to be deported to face justice in the U.S., where she has been charged with murder and unlawfully fleeing prosecution.

Austin police found Wilson, 25, riddled with gunshot wounds in a friend’s home around 10 p.m. on May 11. The California resident is one of the country’s top pro cyclists and was visiting Texas ahead of a competition when she went out for an evening with Colin Strickland, another pro cyclist whom police describe as Armstrong’s boyfriend.

Moments after Strickland dropped Wilson off that evening, according to investigators, Armstrong’s SUV showed up on surveillance video outside.

Colin Strickland Kaitlin Armstrong texas home

The Austin, Texas, home where Kaitlin Armstrong and Colin Strickland live. (Fox News Digital/Michael Ruiz)

The 34-year-old yoga teacher was questioned and released on May 12. By May 17, she was named in a murder warrant. By then, she’d already flown from Texas to New York, where police say she arrived at LaGuardia Airport on May 14.

Costa Rica law enforcement work closely with their U.S. counterparts in such cases, according to Lenny DePaul, the retired former commander of the U.S. Marshals Service’s New York/New Jersey Regional Fugitive Task Force.

"They will deport her, and she'll probably waive extradition -- and then the U.S. Marshals Service will have 10 days to go down and extradite her back to the United States," he told Fox News Digital Thursday.

Federal investigators and their Costa Rican partners were able to track her movements after the trail went cold in Newark, he added.

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"I do know that there were a couple of U.S. Marshals on the ground that were working with the Costa Rican authorities, as well as Homeland Security [Investigations], [and State Department] Diplomatic Security Services as well," he said. "It took them a couple of weeks to really tighten up that noose a little bit and get her in their sights."

As for the sister whom Armstrong may have visited before fleeing the country, DePaul said he hopes for her sake she cooperated with authorities.

Christie and Kaitlin Armstrong

The sisters shown in 2015. (Christie Armstrong/Facebook)

"If not, she's facing significant time," he said. "They could certainly charge her with harboring a fugitive or aiding and abetting. It's a significant amount of time in a federal penitentiary, so I'm hoping she jumped onboard Team USA...[and] did the right thing."

Authorities told FOX 7 Austin Thursday evening that the passport Armstrong allegedly used "was issued to someone else that was in very close physical description" and that she was captured with "a bandage over her nose area" and told police she’d been in a surfing accident.

As Fox News Digital has reported, a man at an upstate New York campground where Christie Armstrong has been staying and working said he saw the fugitive in the area sometime last month, "before the whole thing blew up" and the manhunt made national headlines. 

The sisters share similar physical characteristics, and Marshals previously told Fox News Digital they were aware of the campground.

Kaitlin Armstrong wearing a mask at LaGuardia Airport

Surveillance video shows Armstrong at an airport after she fled Texas. (US Marshals)

Jason Jensen, a Utah-based private investigator who has been following the case, told Fox News Digital that there is a chance Kaitlin Armstrong was using her sister’s identity while on the lam. And a day before Kaitlin Armstrong was seen in New Jersey, her sister allegedly obtained a New York state driver's license, he said.

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Back on May 14, an anonymous caller told Austin police that Armstrong had recently obtained a handgun. Months earlier, according to the tipster, she allegedly grew furious after learning that Strickland was involved in a romantic relationship with Wilson. Police said one of two 9 mm handguns they recovered at Strickland’s home was "significant to the investigation." Armstrong also lived there, according to the warrant for her arrest.

Prior to her capture, Armstrong's last known whereabouts were at Newark International Airport in New Jersey, also about 120 miles away from the camp, on May 18. Marshals said they did not find a record of any departing flights in her name but determined she flew to Costa Rica with someone else's passport.

Kaitlin Armstrong, 34, is suspected of killing professional cyclist Moriah Wilson, 25, on May 11 at the Austin, Texas, residence Wilson was temporarily staying ahead of a bike race.

Moriah "Mo" Wilson, left, and Kaitlin Armstrong. (The Wilson family/ U.S. Marshal Service)

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Armstrong is a former real estate investor and may have a significant amount of cash, according to authorities. And prior to leaving for New York, she sold her Jeep Grand Cherokee to a CarMax dealership around the corner from her house for well below market value at $12,2000, the Marshals said earlier.

Colin Strickland standing outside

Colin Strickland seen outside his Austin, Texas, home on June 17, 2022. (MEGA)

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Police in Austin previously said they’d already recovered the handgun used to kill Wilson after searching Strickland’s house.

No one answered the door Tuesday or Wednesday at the Austin home where Armstrong lived with Strickland, who dropped Wilson off on the night of her murder after they went out swimming and to dinner behind Armstrong's back, according to the murder warrant. Messages sent to his listed phone number were met with a request to "please f--- off" Thursday. 

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According to the warrant for Armstrong, he had bought his girlfriend the pistol earlier this year.