AUSTIN, Texas — The bond between sisters can never be broken – even in death.
It's been nearly 18 years since Roxanne Paltauf was last seen in North Austin. And her three sisters are convinced they have their hands on a very important clue.
"This is our biggest evidence. It's the only evidence we have. It's dated, it's timestamped, it's the most confusing. There's no, like, logic," Ronica Paltauf said. "He made all these phone calls in that span of time."
Ronica, Rosa and Rubi Paltauf have poured over their eldest sister's phone records thousands of times, specifically focusing on Friday, July 7, 2006 – the day their sister went missing.
"At 5:28 p.m., my mom talked to her for two minutes," Ronica Paltauf said.
Roxanne Paltauf told her mom she was planning to stay another night with her boyfriend, Louis Walls, at the Budget Inn off Rundberg Lane and Interstate 35 in North Austin. She was 18 at the time, and Walls was 28 with two kids. Due to their age gap, the sisters say their relationship was never approved by their mother.
The following morning, on Saturday, July 8, Roxanne Paltauf had promised to go back-to-school shopping with her mom and sisters. But she never showed.
"We were very concerned," Rosa Paltauf said.
PHOTOS: Roxanne Paltauf
That night, their mom got a phone call from Walls.
"He was like, 'Hey, have you seen Roxanne?' And we were like, 'Seen Roxanne? She says she was with you. What do you mean?'" Ronica Paltauf said.
Walls told police he and Roxanne Paltauf got into an argument Friday night, and she left the hotel between 9 p.m. and 10 p.m. But her sisters don't buy that story.
"She didn't walk out the hotel room. We both know that. If you were arguing, why would you take off your valuables, leave your cellphone and then just storm out?" Rosa Paltauf said.
There were no witnesses and there is no surveillance video proving she left the hotel.
That brings her sisters back to her phone records..
"After she vanished is when he made like over 300 phone calls. The gap of no phone activity and then immediate panic phone calling shows me that he's scared and he messed up. There's also these roaming charges," Rosa Paltauf said. "Look, ya'll weren't in the Austin area. I don't know what you were doing."
Throughout the years, investigators with the Austin Police Department (APD) have reviewed the cellphone records but said they didn't get them far. Detectives also said Walls has a lengthy criminal history that includes domestic violence, adding that he has always been a person of interest in this case.
Initially, detectives treated this as a missing persons case and believed Roxanne Paltauf took off to get away from Walls. Detectives also told KVUE, "We never wound up getting any type of physical evidence from that hotel where she left from because we didn't have a crime to allege."
By the time police realized the case was more than they initially though, circumstances had changed.
"Hotel rooms had been re-rented, But that kind of changed the way APD investigated missing persons. Now if there are suspicious circumstances, we investigate it as though its a homicide first," an APD detective told KVUE.
Nearly 18 years have gone by and Roxanne Paltauf's sisters only see her in their dreams. They remember her as a sister they describe as protective, loving and like a second mom.
"She took on the role of being the mother, helping us with homework, making sure we ate dinner every night, that the laundry was done," Ronica Paltauf said.
"At the end of the day, Roxanne loved us, loved us hard," Rubi Paltauf said.
"She deserves, you know, she deserves to be laid to rest. We deserve some peace of mind. Some answers," Rosa Paltauf said.
Detectives said they are currently using new technology to examine Roxanne Paltauf's phone records. But they stress this case was challenging from the start because they received so many false leads. Many people claimed they saw Roxanne Paltauf well after she went missing, leading police in many different directions.
Police also told KVUE that shortly after Roxanne Paltauf disappeared, they found her ID on a man named Geoffrey Moore who had been staying a nearby hotel. Moore told officers he gave Walls and Roxanne Paltauf a ride, and she dropped her ID in his car.
KVUE Daybreak's Yvonne Nava is shining a spotlight on several Central Texas cold cases as part of a monthly series called KVUE Crime Files.