On Monday, Annette Leary gave evidence in Dawson's murder trial, saying she had seen Lynette with the bruises at the Sydney children's centre where they both worked.
Ms Leary told the NSW Supreme Court that Ms Dawson had suggested the pair undertake marriage counselling in January 1982 after they experienced marital difficulties.
Dawson was not pleased at the suggestion and physically assaulted Lynette in the lift after the counselling session, Ms Leary said.
"Chris had gripped her throat and shook her a little and said 'if this doesn't work, I'm getting rid of you, I'm only doing it once'."
Ms Leary saw the bruises on a Friday in January 1982. Ms Dawson did not go to work the following Monday, the court heard.
Warriewood Children's Centre manager Barbara Cruise also gave evidence. While she could not remember seeing Ms Dawson with bruises, she said the couple had experienced marital strife at the time.
Dawson, 73, is accused of killing his wife and disposing of her body in January 1982 because he wanted to pursue a relationship with one of his high school students, known as JC. He has pleaded not guilty.
Ms Cruise said that despite being concerned about Dawson's choice to let JC move into their home, Lynette eventually consented.
"I thought she was fairly naive about it," Ms Cruise said.
On January 11, 1982 when she did not arrive at work, Ms Cruise said that Dawson claimed over the phone that his wife had gone away and that he did not know when she would return.
JC also testified on Monday, admitting she had asked author Rebecca Hazel to hurry up and finish her book about Ms Dawson's disappearance so they could make some money, but adding that she she may have said that as a joke.
"We joked about things like that all the time," JC said.
JC said that, although she had been approached about making money from her story by various individuals, she had not actually done anything about it.
JC and Dawson married in 1984 and separated in 1990.
Dawson's barrister Pauline David accused JC of lying about her former husband in 1990 because of an acrimonious break-up.
Ms David claimed JC had lied about Dawson talking with his brother about what would happen to the family home and who would get what if he left his wife. The barrister also alleged that JC lied about insurance taken out at the time, in order to heighten suspicions about her client.
JC rejected these allegations.
The court was taken to JC's earlier police statements which varied from her current version of events around Ms Dawson's disappearance.
Details of an incident when Dawson allegedly considered hiring a hitman to get rid of his wife had changed from JC's first police statement in 1990 to another statement given in 1998, Ms David said.
Claims of Dawson's repeated violence towards JC, including an incident where he allegedly ripped off her g-string, were also not included in her prior affidavits, the court heard.
Ms David said Dawson had, in fact, only been violent to JC once while they were at a Sizzler restaurant.
"During that incident, there was a situation where Mr Dawson grabbed your wrist," she asked.
"Yes," JC replied.
Ms David referred to letters written by Dawson to JC while the pair was breaking up in 1990. At the time, he was living on the Gold Coast and she was in Sydney.
"[JC] you are a good, beautiful person. You have so much to give those who love you. If you ever want my support or help, you know where I am. There is a house full of love up here for you," Dawson wrote.
JC described these letters as lies to get her to return to the abuse and "prison-like state" in which she lived previously.
The judge-alone trial continues on Tuesday.
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