The parents of a student killed at Columbine High School have lost their bid before the U-S Supreme Court to withdraw from a settlement involving the gunmen's families and others.
Justices let stand a ruling by the Denver-based Tenth U-S Circuit Court of Appeals, tossing Michael and Vonda Shoels' claim that they took the deal because of a mistake at their lawyer's office.
The couple alleged the Denver court's ruling unfairly took away their right to go to trial.
Eighteen-year-old Isaiah Shoels was killed in the 1999 attack. Eleven other students, a teacher and the two teenage gunmen also died.
The parents of Eric Harris and Dylan Klebold agreed in 2001 to pay about one-point-six (m) million dollars to at least two dozen families of victims and survivors.
In exchange, the families agreed to drop lawsuits alleging the teens' parents let them amass weapons used in the attack.
The case is Shoels versus Klebold et al, 04-710.