Italian Police Looking for Man Seen in Video With US Woman Later Found Dead in Florence

— -- Italian authorities are close to identifying the man they believe is responsible for killing Ashley Olsen, the 35-year-old U.S. expatriate found dead in her Florence apartment over the weekend, according to Italian news reports.

After analyzing hundreds of hours of surveillance video from cameras, including one on Olsen's street, authorities have turned their focus on a man, possibly a drug dealer, who was spotted on video walking Olsen home and then going inside her apartment building with her, according to media reports.

An preliminary autopsy on Tuesday showed that Olsen had been strangled, officials said. An Italian prosecutor in the case said the killer could have used a thin cord or chain.

Investigators were told by Olsen's friends that they had been out with her at a Florence club called Montecarla on Thursday but that they'd left earlier than she did, according to the Associated Press. That was the last time they saw her.

The club was located 10 minutes away from her rented apartment.

Olsen's naked body was found by her Italian artist boyfriend in her studio apartment nearly 36 hours later, on Saturday afternoon, according to local reports. Police said that her neck showed signs of bruising and scratching. There were no signs of a scuffle, no forced entry and nothing was missing, Italian news reports said.

Olsen was a Florida native. She'd been living in Florence for about three years, according to the AP, after moving to the country to be with her father, Walter Olsen.

In a statement Tuesday, Walter Olsen said: "We are devastated that our precious Ashley has passed away resulting from a horrible and senseless crime."