PASCO, Wash. — Investigators say they have solved the killing of a Richland construction contractor more than three decades ago.

The Tri-City Herald reports that Franklin County prosecutors filed a first-degree murder charge Wednesday against 54-year-old Theodore Milam, who’s already in the Spokane County Jail for several violent crimes dating to 1999.

Investigators say DNA evidence linked Milam to the death of 40-year-old Robert J. McDonald in February 1986. McDonald was found partially clothed, bound and floating face-down in the Pasco Boat Basin along the Columbia River; he had been bludgeoned, and the cause of death was listed as drowning.

It is not yet known when Milam will make an appearance in a Franklin County Superior Court.