02/18/2013 10:42 am ET

Sarai Sierra Shown In Surveillance Images In Istanbul While Turkish Police Question Suspect's Siblings (PHOTOS)

The investigation into the murder of a New York mom traveling in Istanbul unearthed new footage of her walking alone on Jan. 21 -- the day she disappeared.

Turkish police also questioned the siblings of a mystery homeless man they want for questioning in Sarai Sierra's murder.

A clip from a surveillance camera allegedly shows Sierra strolling along an uncrowded sidewalk next to a four-lane road headed towards the historic city walls where her body was found on Feb. 2, according to Turkish news website Hurriyet Daily News. The camera captured Sierra on the last day she was seen alive.

Another newly released image reveals the 33-year-old married mother of two walking unaccompanied near the huge metropolis's waterfront, according to WCBS. This picture was also taken on Jan. 21, the day before she was supposed to catch a flight home, wrapping up her first trip outside the United States.

Her husband and brother flew to Istanbul to look for Sierra after they learned she never checked in at the airport. It took 11 days before police discovered her bludgeoned body near the city's ancient walls.

On Friday, her friends and family bid farewell at her funeral in the Christian Pentecostal Church in Staten Island, the Daily News reported.

A blow to the head killed Sierra, who'd also visited Amsterdam and Munich as part of her two-week trip to pursue her interest in photography. A rock stained with her blood was allegedly found and is regarded as the murder weapon, according to the Daily Mail.

Investigators took DNA samples from at least 52 people, but winnowed their search down to a transient paper collector who frequently hung out near the walls until Sierra disappeared.

In an effort to find the homeless man, Turkish police reportedly detained two of his brothers and a sister in the city of Karabuk, according Fox News Latina.

Reports in Turkish media say that the potential suspect got money from his sister and told his family that he was traveling to a region near the Syrian border.



Sarai Sierra