A sheriff says investigators in the slayings of two Texas prosecutors got their big break from a tip about a storage unit that contained guns and a vehicle tied to the crimes.

When authorities uncovered the storage unit, they also unraveled what they contend was a meticulous revenge plot against the Kaufman County district attorney and a top assistant for their successful prosecution of a former justice of the peace for theft.

That former official, Eric Lyle Williams, and his wife are charged with capital murder in the slayings of the DA, his wife and an assistant prosecutor.

Sheriff David Byrnes says the storage unit was "the watershed event" that helped authorities put everything together.

A friend of Williams' told authorities about the unit.