A Texas jury has convicted a 58-year-old man of the 1986 murder of a woman near Austin whose husband was wrongfully convicted in the case.

He served 25 years in prison before being exonerated with the help of DNA evidence.

Jurors deliberated for about three hours in San Angelo before finding Mark Alan Norwood guilty of beating Christine Morton to death in bed in her home in Round Rock, north of Austin.

Norwood, from Bastrop, Texas, had been implicated in the case through blood and hair samples from a bandana found near the house the day after the murder.

Norwood was sentenced to life in prison after being convicted but is eligible for parole in 15 years.

The victim's husband, Michael Morton, served a quarter century behind bars before DNA evidence helped clear him in 2011 and connected Norwood to his wife's death.

"I've learned so much, I've been through so much," Mr Morton said after the jury reached its verdict.

Outside the courtroom, Mr Morton embraced Norwood's family while a deputy transported Norwood to the Tom Green county jail.

Prosecutors made their case by showing similarities between the Morton case and the 1988 beating death of Debra Baker, an Austin woman. Norwood is also charged with her murder.

In both cases, the slain woman was found in bed with pillows covering her head. Both received six to eight blows to the head.

One expensive item and cash were stolen from each home, but jewellery sitting in plain sight remained untouched.

Texas Department of Public Safety laboratory staff compared Norwood's DNA profile with DNA from a hair found in Ms Baker's bed in 2011 and found him to be a possible candidate.

Norwood's family came to his defence.

"My son, first off, is innocent," said Dorothy Norwood, Mark Norwood's mother. "I know his character. He has had an interesting family life, but he has always been kind."

Connie Hoff, Norwood's sister who lives in California, added, "We understand Michael Morton's journey. Mark is experiencing what Michael went through. History is repeating itself."

The New York-based Innocence Project and Houston lawyer John Raley worked on Mr Morton's behalf to get DNA testing done on the bandana found near the crime scene.