WASHINGTON (AFP) - A judge in Texas received crucial DNA test results on Tuesday from a death-row inmate convicted of killing three people.
The judge now has to decide whether to go ahead with the execution of Hank Skinner, who has been on death row for more than 20 years.
He was convicted of the 1993 killing of his companion Twila Busby and her two children.
Skinner says he is innocent and hopes to prove this with the DNA analysis, which he has been demanding for the last 13 years.
In a two-day hearing that ended on Tuesday, his lawyer Robert Owen said "the DNA testing produced significant and exculpatory results that raise grave doubts about Mr Skinner's guilt and point to an alternate suspect".
Four hairs were found in the hand of Busby at the time of her murder. The DNA tests show that in three of them there was a maternal link between the person the strands of hair came from and the three victims, the lawyer said in a statement.
An expert witness for the state testified that the hairs could not come from the victims themselves because their hair was "visually dissimilar".
The defence lawyer pointed to a maternal uncle of Busby, the late Robert Donnell. He was seen stalking Busby an hour before the killings and showed no remorse upon learning of the death of his niece, said Mr Owen.
A representative for the Texas attorney's office has said the new tests only confirm Skinner's involvement in the killings.
The fourth hair belonged to Skinner. And an initial series of tests showed his DNA was on the weapon used in the attack - a kitchen knife.
But the defence lawyer said Skinner, who lived in the same house, used the knife daily and that the state could not prove Skinner was guilty.
"The State has not presented any dramatic new evidence confirming Mr Skinner's guilt," Mr Owen wrote.
In his statement, Mr Owen denounced the disappearance of a "major piece" of evidence - a bloodied windbreaker jacket found near Busby. Mr Owen said this could corroborate the evidence pointing to Donnell.
Both sides must present written conclusions to Judge Stephen Emmert, who will give a verdict in March at the earliest.