Aug. 3, 2012 -- The family of missing Indiana University college student Lauren Spierer could know in a matter of days if a skull found 60 miles from where she disappeared belongs to the college student.
As she waits for word on the fate of her daughter, Charlene Spierer issued an open letter to those responsible for Lauren's disappearance.
"To Whom This May Concern: It sickens me to write to you once again, but I have no choice," Spierer wrote. "Time continues to pass and I cannot let you forget about Lauren."
The Spierers have frequently posted messages and blogs, appealing to the unknown person who they believe abducted their daughter.
Spierer, 21, vanished on June 3, 2011, after a night out with friends at a sports bar in Bloomington, Ind.
Last month, a fisherman found a skull in White River, under the Raymond Street Bridge, about 60 miles from where Spierer was last seen.
The Bloomington police called the Spierer family to tell them about the finding, according to ABC News' Indianapolis affiliate WRTV. Divers searched the river for additional remains but did not find anything else.
The skull has been sent to a forensic anthropologist, who will try to determine its gender, age and race. A tooth will be extracted from the skull to see if it matches with Spierer's dental records, which are on file in a national database, Charlene Spierer said.
"We wait along with other families of missing loved ones. It could take as long as eight weeks. That's 80,640 minutes of agony," Spierer wrote.
"I hope I am making you uncomfortable. I hope you have as many sleepless nights as I have. I hope that someday, your parents, your siblings, your friends will all be in a courtroom when your true self is revealed."
ABC News' Christina Ng contributed to this report