From Daily Mail
......
Meanwhile, a witness has told Istanbul police that he saw Sierra speaking to a different man outside the city's Sultanahmet Mosque on January 11, just days after she arrived in the country.
He handed her a card and as she left the mosque, she took a walk with him and four or five other men, the witness claimed, Turkish newspaper Milliyet reported.
......
The witness said he then saw Sierra talking with the same man on January 21 at Topkapi Palace - the day she was due to fly home, but she never boarded the flight.
......
I don't believe these could be credible. Look at some of the street view shots from the Yandex site and there are thousands of people out in busy areas. You would have to be very very very distinctive to be singled out to be remembered on two different days. Like a 7 foot tall Chinese basketball player or something. Not a petite dark haired woman conservatively dressed. Just don't buy it.