Sarai Sierra Murder Investigation Focuses On Homeless Man In Istanbul: Report

The investigation into who killed a New York mom vacationing in Istanbul is focused on a homeless man seen in the shabby part of the city where her body was found, the Daily Mail reports.

Turkish police, are hunting down the person who killed Sarai Sierra with a blow to the head and left her near an ancient part of the city's walls. Their only suspect is a paper collector known as "Z," according to the Staten Island Advance.

Witnesses allegedly told police that Z hasn't been seen since he was covered in dirt on Jan. 21 -- the day the 33-year-old was supposed to fly home to her husband and two children in Staten Island.

Sierra's body was found 12 days later on Feb. 2, close to where Z had loitered, the New York Post reports.

Unnamed officials speculated that Sierra was killed after resisting an attempted robbery. Police collected DNA samples from 53 people. The Daily Mail had previously reported that police narrowed their investigation to five people -- an assortment of transients and friends that Sierra had made online before going to Turkey.

She was traveling alone on a two-week trip to Turkey, Amsterdam and Munich to pursue her photography hobby. While away for the first time outside the United States, she stayed in regular touch with family and friends until she was expected to board her return flight.

Turkish media has published reports that she had an affair with a Turkish man in a bar bathroom. The man, speaking through his lawyer, said their friendship was platonic and her husband told WPIX that she didn't cheat on him.

Sierra's wake is scheduled for today in the Staten Island church where she met her husband Steven, according to WCBS. Valentine's Day is the anniversary of the couple's engagement, according to the Daily News.