Police in Italy have detained a Senegalese immigrant in connection with the strangling of an American woman in Florence, a local news agency reported Thursday. 

The Italian news agency ANSA reported that the unidentified suspect was detained late Wednesday based on DNA evidence taken from the apartment of 35-year-old Ashley Olsen.

Olsen was found nude on her bed in her rented apartment on Saturday after her boyfriend had the owner open the door, alarmed that the woman had failed to respond to phone calls. The body had bruises and scratches on the neck, and an autopsy determined that she had been strangled with a cord or a rope.

ANSA reported that investigators had narrowed in on the suspect using video surveillance cameras along the route from the nightclub that showed them together Friday morning, a day before Olsen’s body was found. The man was known to authorities for being involved in the local drug scene.

Authorities released no other details. The lead prosecutor had declined to comment on the case earlier Wednesday, and police officials say they are not authorized to speak to media during the investigation.

Olsen, originally from Summer Haven, Florida, had been living in Florence for three years as an active member of the expatriate community and art scene. She had moved to Italy to join her father Walter Olsen, who teaches in the Renaissance art city.

Walter Olsen issued a statement late Tuesday expressing the family’s grief and confidence that the killer would be found.

“We are devastated that our precious Ashley has passed away resulting from a horrible and senseless crime,” he wrote.

He described his daughter as “a beautiful and creative young woman, with a happy, exuberant and generous soul,” adding: “We are heartbroken she was taken from us.”

He asked that the family be left to grieve in peace and expressed “faith that the perpetrator will be found and sentenced.”

The Associated Press contributed to this report.