A Maryland woman is taking inspiration from an Oscar-winning movie to try to solve the decades-old murder mystery of her twin sister. Twenty-three-year-old college student Jody LeCornu was shot outside Baltimore in 1996. Now her sister hopes billboard ads will help find the killer.

Jenny Carrieri admits she has lost time with her husband and children while consumed in her sister's case. Carrieri told CBS News' Errol Barnett that no one knew her twin sister better than she did. On a snowy March day in 1996 LeCornu went to a bar with some friends after a fight with her boyfriend. Around 4 a.m. she gave someone a ride home, bought more alcohol and made phone calls from a store parking lot.

Jody LeCornu

"That whole night was very out of character for her," Carrieri said. "She never would have done that. Gone to sit in a dark parking lot."



According to police, a witness at a gas station saw a man in a white BMW approach LeCornu's car. The two spoke but as LeCornu began to drive away, the suspect shot her through her car's rear passenger window – severing her spine. LeCornu then somehow drove across the street.



"Once she stopped, he drove up to her car and got out and I think she had died at that point. The witnesses said he reached over her body put her car in park and took something out of it," Carrieri said.



Now, 23 years later with no leads, Carrieri is desperate for answers. Inspired by the Oscar-winning film "Three Billboards Outside Ebbing, Missouri," Carrieri is putting up a series of her own and offering $100,000 to anyone who can help find her sister's killer.

Corporal Shawn Vinson is with the Baltimore County Police Department.

"Right now we're comfortable saying we don't have any leads," said Corporal Shawn Vinson of the Baltimore County Police Department. "I don't want to say exactly what evidence we have and what we don't have."

He added, "We want to be held accountable … Any information that we do receive, though, we are going to follow up on."

For Carrieri, solving her twin's murder means finding peace. "Please come forward, this is just ripping me apart."

Carrieri said her family has sued for access to the autopsy report or the original police report. We also tried to track down that information and were told by the state attorney's office it won't release the documents because it's an active investigation.