HUNTSVILLE -- A 29-year-old East Texas man was executed Thursday evening for fatally shooting one of the three people he and a partner abducted during a convenience store robbery in 2002.Richard Cobb didn't deny fatally shooting a mentally disabled man with a 20-gauge shotgun in a field outside Rusk. Two women also were shot, and one was raped."Life is death, death is life. I hope that someday this absurdity that humanity has come to will come to an end," Cobb said when asked if he had any last words. "Life is too short. I hope anyone that has negative energy towards me will resolve that."Life is too short to harbor feelings of hatred and anger. That's it, warden."But that wasn't it.Just before the lethal drug took effect and at the conclusion of his statement, Cobb twisted his head back, raised it off a pillow placed on the gurney and then toward the warden standing behind him."Wow!" the inmate exclaimed in a loud voice. "That is great. That is awesome! Thank you, warden! Thank you [expletive] warden!"His head fell back on the pillow, and his neck twisted at an odd angle, with his mouth and eyes open.He remained that way for some 15 minutes before a physician entered the death chamber to examine him and pronounce him dead at 6:27 p.m.The father, stepmother and stepbrother of Kenneth Vandever, the man Cobb killed, were among the witnesses. Also in the viewing area was one of the women who was shot and attacked but survived to testify against Cobb.Earlier Thursday, the U.S. Supreme Court rejected his final appeal. Cobb's lawyers from the Texas Innocence Network contended that a prison expert at his trial in 2004 falsely described how much freedom the convicted Cobb could expect if jurors gave him life in prison rather than a death sentence.On Sept. 2, 2002, Vandever and the two women were abducted from a store in Rusk, about 120 miles southeast of Dallas, and taken to a field about 10 miles away. All three were shot and left for dead.Vandever, 37, died, but the women managed to get help and later testified against Cobb and his partner, Beunka Adams.Cobb was 18. He testified at his trial that he began using drugs at age 12 and turned to robbery to pay off a drug debt.Adams was executed a year ago this week.