OIJ found the body Monday afternoon near the Airbnb property where Stefaniak had been staying when she went missing November 27 in San Antonio of Escazú, San José.
Espinoza told WSVN that all data gathered in the case shows the body is her's, but officials are waiting to compare the fingerprints with Federal Bureau of Investigation records.
Family members said the owner of the Airbnb told them a guard reported seeing Stefaniak get into a vehicle with her bags around 5 a.m. on November 28.
Stefaniak was in Costa Rica celebrating her birthday with her sister-in-law.
The family of former Tampa resident Carla Stefaniak, who disappeared while vacationing in Costa Rica, says a body found on Monday is hers. Espinoza told Spanish-speaking media that Martinez, of Nicaragua, was arrested at about 11 p.m. Monday after authorities raided his apartment, which was adjacent to the room Stefaniak and Burton rented through AirBnB.
A US State Department representative had told CNN that officials were aware of the reports of a missing American in Costa Rica. It was discovered partially buried in plastic bags in a mountainous area.More news: Here's Every Video Game On Sale For The Game Awards
"Words can not express how shocking and devastating this is to her family and her friends", Antonieta wrote on Facebook.
"I have hope that the body found is not my daughter's", he told reporters before his worst fear was confirmed.
The two texted each other via WhatsApp throughout the day, Burton said, until Stefaniak suddenly stopped responding to her messages that evening.
Witnesses supposedly saw Stefaniak leaving the Airbnb around 5 a.m. with her luggage and getting into an unknown auto, according to the Miami Herald.
Burton told CBS News this week that a rainstorm appeared to knock out the power at Stefaniak's Airbnb.
The suspect, who has a surname Espinoza Martinez, is a 32-year-old Nicaraguan immigrant who has been in Costa Rica since June.More news: Russian Federation launches first manned voyage to ISS since rocket accident
"Every time we travel, she always used that resource", Jaime said.
"Since 2013, Villa Le Mas has operated a small vacation rental facility located at San Antonio, Escazu, Costa Rica".
Bugra Demirel told the BBC: "It's a terrible wait, and every single minute that Costa Rican officials are not showing the body is just a tremendous amount of pain on the family".
During an exclusive interview with ABC Action News, Stefaniak's father, Carlos, said his heart shattered when he saw her body.
"As a effect of this tracking, at midday we found the decomposing body of a person and according to preliminary investigations it's the body of a woman", stated Chief Walter Espinosa of the Costa Rican Judicial Police force. "That's the last we heard from her".
"We all remain very hopeful and very positive that she will be found alive and safe", he said. However, an Uber driver she scheduled to pick her up still showed up at 8:30 a.m. Jaime said.More news: Did Offset Cheat On Cardi B? Multiple Alleged Mistresses Speak Out
That same night, she was Facetiming with a friend in NY when the call dropped about 9pm.