NEW YORK (AP) — The FBI is playing a significant role in the investigation into the death of a New York City woman in Istanbul while on a solo vacation, a U.S. congressman said Monday.

Rep. Michael Grimm, a former FBI agent, said U.S. investigators were invited by Turkish authorities to assist as they try to find out what happened to Sarai Sierra, a 33-year-old mother of two who disappeared Jan. 21. Her body was found 12 days later, near the remnants of the city's ancient walls. Police said she had suffered a fatal blow to the head.

Prosecutors in Istanbul got a court order Monday for authorities to take blood and DNA samples from 21 people already questioned in the death, according to Turkish state media.

Meanwhile, her family was working out how to return her body to the U.S.

"Our No. 1 priority right now is bringing Sarai home," said Grimm, who accompanied Sierra's parents, Betzaida and Dennis Jimenez, as they spoke to the media at the home of a family friend on New York's Staten Island.

Sierra's husband, Steven, is in Istanbul, where he traveled last week to help in the search. He intends to accompany her body back to New York, but the family is still determining how to fund the transport. Their church and friends are working to raise money to help defray the costs.

Turkish authorities finished an autopsy Monday on Sierra and gave DNA samples from it to a crime lab, the state-run Anadolu Agency reported. After that, Istanbul prosecutors got the court order but did not identify the possible suspects, the agency reported.

On Monday, police with sniffer dogs were scouring the area where the body was found for clues, it said. The Milliyet newspaper said the forensic lab will examine samples from Sierra's fingernails as well as hair and other samples from a blanket found near her body. It said some nail scrapings suggest she may have tried to fight off at least one attacker.

Sarai Sierra made her first trip overseas alone after her childhood friend, Magdalena Rodriguez, backed out. At Monday's news conference in New York, Rodriguez fought back tears as she said she wished she had not changed her plans.

"I wasn't working at the time and I didn't have the money to go," she explained.

Family and friends described Sierra as a devoted mother to her 9- and 11-year-old sons who volunteered at their school and worked part time so she would be available for them after school. "Every time I saw her, she was always with her family," said another longtime friend, Dulce Arroyo.

Arroyo ran across Sierra on a shopping trip two days before she left the U.S. and said traveling alone didn't appear to be a frightening prospect. Her friend was looking forward to an exciting adventure and spent most of their conversation talking about the murals and architecture she planned to photograph.

"She was perfectly OK with taking this trip on her own," Arroyo added. "She was thrilled."

Dennis Jimenez said Sierra tried to calm any fears by emphasizing that she'd be in regular contact via video calls and text messages.

"I didn't want her to go, but she wanted to go," he said. "Turkey was a land rich in architecture and ancient history, and she was very fascinated by that." Continued...