Indianapolis ? Gov. Mitch Daniels rejected the request of a convicted murderer for a reprieve of his execution so he could donate part of his liver to an ailing sister.

The decision was announced about 12 hours before Gregory Scott Johnson, 40, is scheduled to die by lethal injection early today at the Indiana State Prison. The Supreme Court on Tuesday also denied a stay of execution.

Daniels said he found “no grounds to second guess years of court rulings or to reject the recommendation of the parole board.”

The board recommended on Friday that Daniels deny clemency or a reprieve, saying Johnson was guilty of the beating death of 82-year-old Ruby Hutslar and should be put to death as scheduled.

Daniels said he accepted the sincerity of Johnson’s motivation in trying to donate part of his liver, but said medical experts had advised against it, saying Johnson’s sister would be better served by accepting a new organ through the conventional process.

Johnson’s 48-year-old sister suffers from nonalcoholic cirrhosis.

The governor’s office released a letter Daniels received from two transplant doctors who said the presence of a hepatitis B antibody in Johnson’s system and his heavy body weight made him unsuitable as a donor.

Given the sister’s condition and the fact that she likely will need a kidney as well, she would be better served by obtaining a full liver and kidney from the same donor through customary channels, the letter said.

Johnson was convicted of breaking into Hutslar’s home in 1985, beating and stomping on her, then setting a fire to hide his crime. The state has said he admitted to the killing but changed his story after his conviction.