The convicted killer of a Houston man gunned down during a botched burglary nearly 18 years ago was executed Wednesday evening after apologizing for the killing.

"I'm sorry for all the pain I might have caused you and your family," Kenneth Wayne Morris said to three of the victim's sons and a grandson. "I carry nothing but love in my heart. I pray one day y'all can forgive me."

Morris told two friends watching that he loved them, and said he was "ready to go home." He was pronounced dead at 6:16 p.m., eight minutes after the lethal drugs began flowing.

Morris, whose 38th birthday was Wednesday, was the 10th condemned murderer executed in Texas this year and the second in as many nights to receive lethal injection.

The U.S. Supreme Court refused to stop the execution less than 30 minutes before he was scheduled to be taken to the death chamber.

Attorneys for Morris had sought to overturn his death sentence or delay the punishment, contending the Harris County district attorney's office unconstitutionally discriminated against Morris in seeking the death penalty against him because he is black.

Roe Wilson, a Harris County assistant prosecutor handling Morris' appeal, said it would be "ludicrous to assert that Harris County sought the death penalty against Morris for a discriminatory reason."

In 2003, Morris was within about two hours of execution when he won a court reprieve to investigate claims he may be mentally retarded and ineligible for the death penalty. Those issues were resolved last year.

Morris was condemned for the 1991 shooting of James Adams, 63, during a home break-in. Evidence showed Morris and two companions were looking for a place that had numerous expensive weapons but got disoriented as they drove around the neighborhood and picked the wrong house.

Adams gave them more than $1,000 in cash but no guns. He was shot and fell into a closet where his wife was hiding from the intruders.

The three burglars left behind garbage bags, one of which had a fingerprint that led police to arrest Christopher Montez, then 18. He led them to Morris.

Morris was arrested in Brenham, about 100 miles northwest of Houston, 12 days after the shooting. Montez's cousin, Orlena Ayers, then 20, got life in prison for his part in the robbery, and Montez received 85 years.

On Tuesday, convicted killer Willie Pondexter was executed for a fatal shooting of a woman during a home burglary in Clarksville. Two more executions are set for next week in Texas, the nation's most active death penalty state.