May 20 (UPI) -- Texas executed a 49-year-old death row inmate for the gruesome murder of a grandmother during a robbery in 2012, making him the second person to be executed in the United States on Tuesday and the 18th person this year. Matthew Lee Johnson was killed by lethal injection Tuesday evening at the Texas Department of Criminal Justice In Huntsville, located about 70 miles north of Houston. He was pronounced dead at 6:53 CDT, Attorney General Ken Paxton said in a statement . Johnson