A Tampa man was convicted Monday and sentenced to two life terms in the 1990 murder of a Lawrenceville, Ga., businessman. Kenneth Daniel Howard, 25, was convicted of shooting Thomas Edgar Couch on Sept. 25, 1990, during a robbery at the 55-year-old man's home. Bobby Edward Perez, 19, of Cedartown, Ga. and Robert DeWayne Wilson, 20, of Sevier County, Tenn., also are charged in the slaying. Perez testified Wednesday that he saw Howard pull the trigger. In handing down the maximum of two life sentences, Judge Richard T. Winegarden ensured that Howard would serve at least 20 years before becoming eligible for parole. Defense attorneys vowed to appeal the convictions on felony murder, armed robbery and burglary counts.