McAlester, Okla. ? A man convicted of killing three people 10 years ago in retaliation for an earlier attack on himself was executed Tuesday night in McAlester.

Richard A. Thornburg Jr., 40, was convicted of the September 1996 shooting deaths of James Poteet, 51; Terry Shepard, 39; and Keith Smith, 24. The three killings occurred at Poteet’s house in Alex, about 50 miles southwest of Oklahoma City.

Thornburg had been shot about a month earlier, and believed Poteet was responsible. Prosecutors also said the two had argued over drug money.