Dennis Dowthitt, 55, was executed for sexually abusing...

Dennis Dowthitt, 55, was executed for sexually abusing and killing a Montgomery County teen on June 13, 1990. "I'm sorry for what you had to go through. I am so sorry what you all had to go through," Dennis Dowthitt, 55, said twice. Dowthitt was condemned for raping and fatally slashing and stabbing Grace Purnhagen, 16, in an attack where the girl's 9-year-old sister, Tiffany, also was strangled. He was pronounced dead at 6:18 p.m. CST, 7 minutes after the lethal dose began. On Tuesday, Dowthitt lost an appeal before the U.S. Supreme Court. The Texas Board of Pardons and Paroles, voting 18-0, refused his clemency request on March 6.