An Atlantic County family is going to great lengths in a quest to get answers about the death of their daughter who was killed by a train four years ago.

Tiffany Valiante, 18, was found dead in July 2015 after being hit by a train in Galloway. Investigators ruled the death as a suicide. But her family is not convinced. They are now mortgaging their home, posting a $20,000 reward and asking to pay for DNA tests in an effort to find out what really happened to their daughter.

"I know my daughter didn't do this. I feel it. I know it,” says mother Dianne Valiante.

Dianne says that Tiffany disappeared from the family’s backyard in the middle of a family party. Four hours later she was found dead. Dianne says that Tiffany had a scholarship to play college volleyball, dreamed of becoming a police officer and was planning a trip to Great Adventure the next day.

"I've told clients in the past if they have no case. I can't tell the Valiantes that they should stop in their pursuit of the truth,” says attorney Paul D'Amato.

D’Amato says that the family believes that New Jersey Transit police botched the investigation into the death and too quickly ruled it a suicide.

"With all due respect to them, they didn't have the education or the experience to conduct a murder investigation,” D’Amato says.

D'Amato filed a lawsuit demanding NJ Transit release DNA swabs so they can be tested at the family's expense. He says that he points to discrepancies in the case, from the trainee engineer who changed the story of what he saw multiple times to no drugs or alcohol being in Tiffany's system, to her shoes being found one mile away from the train tracks.

"There is no way Tiffany would have walked five miles given her fear of the darkness,” says D’Amato. "Somebody picked her up shortly after her mother saw her outside the home, and transported her to the point of impact."

"I know Tiffany wants me to fight for her. I know it. And I truly believe one day we'll get her justice. I have faith in that. And I'm going to prove everybody wrong,” Dianne Valiante says.

A spokeswoman for NJ Transit declined to comment about this story, stating that it is agency policy to not comment on pending lawsuits.