Armstrong was captured in Costa Rica on June 29 and deported to the US on July 2 to face charges of murder.
CNN contacted an attorney listed as representing Armstrong on Thursday.
Wilson was found dead with multiple gunshot wounds at a friend’s home, authorities said. She had told her boyfriend that she was going for an afternoon swim with Colin Strickland, 35, a professional cyclist and Armstrong’s boyfriend. He told police he and Wilson swam and ate, and he dropped her off at the friend’s house, according to an affidavit in the Travis County court.
Researchers have said romantic jealousy may have been a motivating factor in the murder.
Armstrong’s trip in Costa Rica took her from the capital San Jose to Jaco Beach and Santa Teresa Beach, said Deputy US Marshal Brandon Filla, a spokesman for the US Marshals office in Austin. Both Jaco Beach and Santa Teresa Beach are located on the Pacific coast.
“It was discovered that Armstrong used different names, aliases, under the alias of Beth Martin, Liz and Ari Martin,” Filla said during a news conference on Thursday. Armstrong used these names in yoga studios and other accommodations, he said.
Filla did not identify whose passport Armstrong would have used.
While in Costa Rica, Armstrong “tried” to actually build something so she could teach yoga, Filla said.
But investigators tracked her down, using “old-fashioned law enforcement techniques,” he said.
Investigators focused on the bus Armstrong took from the San Jose airport. “They knew the route of that bus, so that’s where they started with boots on the ground,” he said.
She also used the aliases for her signature, and “that really started the path of narrowing a path on Kaitlin Armstrong,” Filla said.
She had also changed her physical appearance. “She dyed her hair brown. She cut her hair shorter to about shoulder length,’ Filla said.
The officials went door to door to conduct interviews at yoga institutions and hostels, which led them to Santa Teresa, where she was taken into custody.
But life as a fugitive seemed to be taking its toll.
“When I talk to the foreigners there in Costa Rica, I would say she was exhausted,” Filla said, adding: “When she was met by uniformed officers in Costa Rica, she didn’t give her true identity at first, but when she was taken into custody and interrogated, you know, minutes later, when she finally confessed her true identity.”
Armstrong was arrested, according to Filla, for violating Costa Rican law for fraudulently using a passport.
According to prison records, she is housed in the Travis County Jail in Austin. Armstrong also faces an additional federal charge for illegal flight to avoid prosecution.
Rebekah Reiss and Steve Almasy of CNN contributed to this report.