The family of a Florida woman found dead on the side of a highway said they believe the man she was on a first date with left her after she somehow fell off the back of his motorcycle.

Attorney Todd Falzone, who is representing the family of Jennifer St. Clair, said at a press conference Tuesday that she was picked up around 10 p.m. Thursday by a man she had met on the dating app Tinder. St. Clair's date arrived at her Fort Lauderdale home on a motorcycle with two other couples, who were also on motorcycles.

The group was headed to a bar or restaurant in downtown Delray Beach, Falzone said.

He said St. Clair, 33, was only supposed to be gone for a couple of hours and her family became concerned when they had not heard from her.

Jennifer St. Clair Courtesy Todd Falzone

She was found dead on Interstate-95 in Pompano Beach early Friday.

Authorities said she was struck by three cars while lying on the road, and it's unclear if she was wearing a helmet, according to a police press release. Police have not released the name of the man her family said she was with, and an official cause of death is not yet available.

Falzone said at the press conference that the family believes the man was taking St. Clair back home when she somehow fell off the motorcycle. They said that from what they were told the man left the scene. One of the other couples with St. Clair and her date may have called 911, Falzone said.

"We're still trying to process this. We are trying to get closure," St. Clair's aunt, Amy Gamber, said. "She was a very sweet girl who would do anything for anybody."