On Monday, the parents of missing Indiana University student Lauren Spierer said in a taped interview with Katie Couric they've been "stonewalled" by the last people to see their daughter alive.
According to ABC News, police said only one of Lauren's friends voluntarily came forward to share information in the investigation.
Robert Spierer, Lauren's father, said he's "frustrated and angry" with their daughter's male friends, who were the last to be seen with Lauren on June 3, 2011 -- the night she disappeared. "Despite their claims of doing whatever they could do," Robert said, "the fact of the matter is they refused to meet with us except for one of the boys."
"I truly don't think it was a random abduction," Charlene Spierer, Lauren's mother, said in her interview with Couric. "I think that somebody that Lauren knew was responsible for the events of that evening.”
Robert told Fox News it's possible his daughter was drugged at Kilroy’s Sports Bar, a college bar where she was partying the night she vanished. "She could have been given something in her drink, unknowingly, that made her almost incapacitated," Robert said.
Lauren Spierer reportedly left her cell phone and shoes at Kilroy's. Police said she left the Bloomington, Ind., bar with Corey Rossman at 2:27 a.m. She was also with David Rohn, Mike Beth and Jay Rosenbaum that night.
Fox News notes Spierer was seen leaving the apartment building at 2:42 a.m. with Rossman and walking toward Rosenbaum and Rossman’s apartment complex.
Rossman claims he was injured in a fight on the fifth floor of Spierer's apartment building and doesn't remember anything else. Rosenbaum claims Spierer spent some time at his apartment with him and Beth, but he then watched her from his balcony as she walked away barefoot at 4:30 a.m.
A year and a half after Spierer's disappearance, no arrests have been made and police say the investigation is ongoing. The student newspaper, the Indiana Daily Student, recently marked the 18 months that have passed by spotlighting the 101 people currently reported missing in the state.
At this point, the Spierers told Couric, they're beginning to believe Lauren may be dead. "I understand that Lauren may no longer be with us," Robert said. "We ache for her. We want to bring her home."