Billy Lee Warren, a 20-year plus employee of Wilbert Burial Vault Co. and American Wilbert Vault Corp., was found guilty on Jan. 27 of killing of his former plant manager, Glenn Schulz, and Schulz's wife Betty. Chicago Suburban Newspapers' Reporter/Progress noted that the crime took place in the couple's Downers Grove, Ill., home in May 1978; despite suspicions surrounding Warren, it remained a cold case through 2001 due to his apparent alibi and the absence of a murder weapon — a knife — and other evidence. Downers Grove police charged Warren with the crime in 2001 after his brother Gene refused to support the alibi.

Glenn Schulz was manager of Wilbert Burial's nearby plant in another western Chicago suburb, Broadview. American Wilbert staff testified during the nine-day DuPage County (Ill.) Circuit Court trial that Schulz was a no-nonsense boss bothered by Warren's consistent tardiness on a job that included pouring and demolding precast concrete burial vaults. Now 53, the defendant continued working for Wilbert Burial until the Broadview plant closed in the mid-1980s, then shifted to a Chicago plant now operating under licensee, American Wilbert Vault. The latter company is based in Forest Park, Ill., and operates a second plant and a warehouse serving greater Chicago. Wilbert Inc. maintains the Broadview plant for vault and other product development. It is among funeral industry specialists licensing production of conventional and premium burial vaults to precasters throughout the country.