Costa Rican authorities said Tuesday that they found what appears to be the body of Carla Stefaniak, a U.S. tourist who went missing nearly one week ago. A local security guard was taken into custody in connection with her disappearance, officials said.

An autopsy determined the body initially matched Stefaniak, but investigators were still comparing fingerprints to confirm the identity, said Walter Espinoza of the country’s Judicial Investigation Department. He said the victim died of stab wounds to the neck and upper torso and suffered an additional blow to the head.

Bismarck Espinoza Martinez, 32, was identified as the security guard who was taken into custody, CBS Miami reported. His statements to police did not align with surveillance video from the apartment complex, Espinoza said.

The body was discovered Monday partially buried and inside plastic about 320 yards away from the Airbnb. Espinoza said investigators also found blood inside the apartment.

Stefaniak, a South Florida resident, was in Costa Rica celebrating her 36th birthday. Family members said she missed her return flight home on November 28. They received texts from her the night before around 8 p.m., but then all communication stopped.

Carlos Caicedo, Stefaniak’s brother, said the owner of the Airbnb told him a security guard saw his sister get into a car with her bags at 5 a.m. the morning of her flight. Caicedo said something didn’t add up because his sister’s flight was scheduled for 1:30 p.m. later that day and she was “never early for anything.”

April Burton, her sister-in-law, spent the week in Costa Rica with Stefaniak. She left the day before her sister-in-law and told CBS News “it seemed so safe” when they were together.

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