Sierra's last contact was reportedly a Turkish man who was using the name Taylan online. The two arranged to meet by Galata Tower on Jan. 21, according to online chat transcriptions. After Sierra's husband, Steven Sierra, handed over transcripts of her Gmail, Facebook and Twitter correspondence to police, Sierra's activity during her time in the city was tracked and police were able to discover the identity of Taylan as well as photographs of him. However, his identity has not been made public by police.
According to Sierra's email transcripts, she sent a message to Taylan in the morning on Jan. 21, the day of her disappearance, but it was not delivered. She then immediately left her accommodation after sending a second email in which she told Taylan that she would meet him at Galata Tower at 12:45 p.m. After examining hundreds of hours of security camera footage, police said they were able to identify Sierra for the last time at 11:33 a.m. on İstiklal Street on the day she was planning to meet Taylan.
Sierra, 33, came to İstanbul on Jan. 8. She stayed for 13 days in the basement-floor room of a small house on Kömürcü Zeynel St. in the backstreets of Beyoğlu. She paid online in advance. The mother of two contacted her family for the last time on Jan. 21, the day she was supposed to begin her journey home to New York. That was the last time they heard from her.
Police are continuing to examine video footage taken from 500 security cameras that cover the areas of Beyoğlu, Eminönü, Galata Tower and Karaköy to trace Sierra's whereabouts during her stay and travel in and around the city.