The murder trial of former school teacher Chris Dawson has heard claims his wife Lynette wanted him to seek professional help to deal with the anger he had towards her.
Mr Dawson is accused of murdering his wife Lynette Dawson on or around January 8, 1982, and disposing of her body, possibly with the assistance of others.
The former professional footballer says Ms Dawson left their Bayview home of her own accord, but the Crown alleges the now 73-year-old wanted to "get rid" of his wife so he could have a relationship with a school girl he taught.
Ms Dawson's remains have never been found and Mr Dawson has pleaded not guilty to her murder.
Today, Ms Dawson's sister, Helena Jenkins, gave evidence.
She told the court that weeks before her sister's disappearance, Ms Dawson had complained about her husband's temperament.
Ms Jenkins told the court her sister had said Mr Dawson had "black flashing eyes" and had pushed her away when she tried to hug him.
"She thought he needed to see a doctor to see if there was some physical cause [as to why] he would react to her in such an angry way," Ms Jenkins said.
Diary entries and letters by Ms Dawson's mother, Helena Simms, were later read out to the court and in one letter dated January 4, 1982, she also noted that "Lyn wants Chris to see a doctor to see what is making him so angry".
Mr Dawson has acknowledged he and his wife had relationship issues for a variety of reasons, including his affair with the school girl, but alleges that on January 8 the pair went to a marriage counsellor and were in good spirits.
In another letter, penned a year after her daughter vanished, Ms Simms wrote about how Mr Dawson came to her house to drop off Lynette's belongings in 10 black garbage bags.
She said the school girl, who had always been the family's babysitter, sat in the car out the front of the house and watched on.
Ms Simms wrote that Mr Dawson was "sick" of having the bags in his study and had packed things liked her gardening gloves, nursing uniform and badge and a garter that she wore on their wedding day.
She said the couple's daughter, Sherryn, had told her that "we hope they don't find mummy in the holidays, [the school girl] wants to marry Daddy".
Mr Dawson and the school girl, who cannot be named for legal reasons, did wed in 1984 but separated in 1990.
In December 1981, Mr Dawson suddenly left the family home without any warning to go on a trip with the babysitter to Queensland.
Ms Jenkins said her sister told her a note was simply left on the couple's bed saying "don't paint too dark a picture to the girls".
During cross-examination Ms Jenkins told the court her sister was willing to stand up for injustice and make independent decisions but that she had become a "coward" by late 1981.
She said, for some time, she thought it could be a "possibility" that Ms Dawson left due to the pressure she was under at home but that she hadn't discounted the fact something "more sinister" could have happened.
Mr Dawson's defence case will rely on alleged sightings of Ms Dawson around Sydney after she was reported missing.
