Updated

Texas has executed a man convicted of killing two Houston opera singers nearly 22 years ago.

Forty-two-year-old Derrick Jackson declined to make a final statement before the lethal injection was administered Tuesday. He was the 15th person to be executed in Texas this year.

Jackson contended he was unfairly convicted of the September 1988 fatal beatings and slashings of Forrest Henderson and Richard Wrotenbery. The two 31-year-old men were in the Houston Grand Opera chorus.

The slayings inside Henderson's apartment went unsolved until 1995, when a bloody fingerprint from the scene was matched to Jackson. By then, Jackson already was in prison serving a 12-year term for aggravated robbery.