Fairfax officials have kept schools open in spite of written threats to children that were part of a letter found at the scene of last Saturday night's shooting in Ashland.
School officials have limited media contact with schools although CNN broadcast from outside one of the county's alternative high schools yesterday morning.
"Obviously, the paramount issue here is how we are grappling with the threat to the welfare of our children," Warner said.
"We will do everything to bring this individual or individuals to justice," Warner said.
"Cooperation between law enforcement agencies involved in the sniper case is unprecedented nationwide," Warner told hundreds of educators and business leaders at a Tysons Corner event sponsored by the Fairfax Education Foundation and AT&T.
The crowd celebrated the success of the foundation and its relationship with public schools.
Entertaining the group were the choral and band groups from Marshall High School.
The foundation has poured more than $15 million into schools, much of that being spent on technology. It was the foundation that helped raise money that led to the creation of Thomas Jefferson High School for Science and Technology.