A man who shot dead his sleeping wife and then raped and killed his young stepdaughter 22 years ago has been executed for the 10-year-old's murder.

Chadwick Banks

Chadwick Banks, 43, was pronounced dead after a lethal injection at Florida State Prison, the office of governor Rick Scott said.

Banks was condemned for the September 1992 killing of 10-year-old Melody Cooper. He also received a life sentence for the murder of his wife, Cassandra Banks, in the attack in the Florida Panhandle region.

Banks wore the white skullcap of the Muslim Brotherhood before the lethal drugs were administered, looking directly at the family of the victims when he delivered his final statement.

"I'm very sorry for the hurt and pain I have caused you all of these years," he said.

Authorities said Banks was drinking and playing pool at a bar before going home on the night of the killings. He shot his wife point-blank in the head and then raped and shot his stepdaughter, according to authorities.

Banks, who was 21 at the time, received a life sentence for his wife's murder, and a jury recommended the death penalty for the stepdaughter's killing.

The execution was the eighth in Florida this year and the 20th since Mr Scott took office in 2011. That is one fewer than under Jeb Bush during both of his terms. Mr Bush presided over the most executions since capital punishment was reinstated in the state in 1979, but Mr Scott has just been re-elected to a second term.

Banks ordered a last meal of fried fish, chips, banana pudding and ice cream, said spokeswoman Jessica Cary with the Florida Department of Corrections. Fourteen family members visited him and he spent time with a spiritual adviser.

On the night of the killings, Banks was drinking at a pool hall in Quincy, about 20 miles from Tallahassee, the state capital. His wife left the bar without him and he left about an hour later and went to their home, finding her asleep. According to authorities, Banks shot her and then went into his stepdaughter's room where he told police he molested her for about 20 minutes before shooting her in the head.

Ms Banks's mother Annette Black said after the execution that she appreciated Banks's apology and said she hoped his case would serve as a lesson to people before they make bad decisions while using alcohol or drugs.