(CNN) -- The mother of missing Oregon boy Kyron Horman filed a civil lawsuit against the boy's stepmother Friday, alleging she is responsible for his disappearance and demanding she reveal his whereabouts.
The suit also seeks damages of $10 million.
"I hope that I am wrong, but I fear that he is gone forever," said Kyron's mother, Desiree Young. Her son was last seen on June 4, 2010, inside his Oregon elementary school.
His stepmother, Terri Horman, told police that she'd dropped off the boy that morning at Skyline Elementary School in Portland, Oregon.
"I believe that Terri Horman knows where Kyron is. I believe that Terri Horman is responsible for where my son is. The time has come for Terri to take responsibility for what she has done and to tell me and my family where Kyron is and how he got there," said Young, struggling to speak through tears.
Any money recovered through the suit will go toward helping families and parents of other missing children, she said.
Since Kyron's disappearance, most of the speculation has focused on the boy's stepmother.
In August 2010, investigators solicited the public's help for information about the location of the white pickup truck that she is believed to have driven the morning of then-7-year-old Kyron's disappearance.
And in divorce filings, the boy's father, Kaine Horman, said he believes his estranged wife, Terri Horman, "is involved" in the boy's disappearance. Court documents also allege Terri Horman tried to hire a man to kill her husband.
Still, no charges have been filed against anyone in the case, nor has anyone officially been named as a suspect -- including Terri Horman.
On Friday, Horman's attorney released a statement, declining to comment on the suit.
"Until such time as I have had an opportunity to thoroughly review the complaint, I will not be making any public statement with respect to this matter," Stephen Houze said in a statement.
The civil suit was filed when it was because there is a two-year statute of limitations on such claims, said Young's lawyer Elden Rosenthal.
There is no such statute for a murder charge in the criminal justice system, he said, stressing his client's belief that criminal charges will eventually be filed against Horman.
"Until I can bring Kyron home, I will not rest. It's time for there to be answers," said Young.