CROWN POINT, Ind., May 18 A Gary, Ind., man pleaded guilty to killing his cable installer on learning his TV set was not "cable ready." Fransuah Mathews will spend 20 years in prison as a result of a plea agreement in a Crown Point, Ind., courtroom Thursday. He pleaded guilty to voluntary manslaughter in the deal, the Northwest Indiana Times reported Friday.Mathews killed Verndell Warmack, 39, in August 2004 when Warmack failed to get cable up and running on Mathews' TV, court documents said.Mathews told the court Warmack had agreed to hook him up in exchange for paying off a debt.When a picture failed to materialize on his set, Mathews went outside and shot at Warmack, who was on a ladder trying to make the installation work, the newspaper said. Warmack jumped off the ladder and tried to flee but Mathews fired again, striking him in the chest and leg.Copyright 2007 by UPI