(CNN) A district attorney is lamenting his office's inability to prosecute any sex abuse allegations against Catholic priests detailed in a Pennsylvania grand jury's report this week.

In Tuesday's report, the grand jury said internal documents from six Catholic dioceses in Pennsylvania showed that more than 300 "predator priests" were credibly accused of sexually abusing more than 1,000 child victims since 1947.

Ninety-nine of the 300 priests were in the Pittsburgh Diocese, and about a third of those 99 were in Beaver County, northwest of Pittsburgh.

But because of a variety of factors -- such as the statute of limitations expiring, or the accused or accusers having died -- none of those roughly 30 Beaver County cases can be prosecuted, District Attorney David Lozier said.

Often, he said, the most his office can do for victims is offer solace.