On the first day of his trial, 52-year-old Karl-Heinz B. admitted in a Heidelberg regional court Thursday to killing a pediatrician, his wife and assistant on Dec. 23, 2002. The defendant said he had been too drunk at the time of the killing to remember the exact circumstances. The man said he had set out to rob the doctor in order to have enough money to celebrate Christmas and never intended to kill his victims. However, prosecutors say the man, who was armed with a pistol and a dagger, forced his victims to produce checks and bank cards before strangling them to death. Police arrested the father of two about six weeks after the cold-blooded killings. If convicted, he could face more than 15 years in prison.