Both said they feared their mother was dead when they heard from a neighbor there had been a shooting.
And both said they were angry at their father, who has been in jail and whom until Thursday they had not seen since the shooting.
Thayne Scott, 18, described an argument his parents had last year over how to spend their tax returns. Tracy Scott wanted to buy a new weapon, but Teresa Scott wanted to spend it on the roof.
His dad yelled and screamed at his mom, Thayne Scott said, noting that his mother was "not as mad as he would get."
The family was going to a Christmas party two or three years ago, when someone remembered the garage door was not closed. That resulted in a fight in which his father punched his mother in the stomach, Thayne said, and the man was arrested on suspicion of domestic violence.
Thayne Scott said he never saw his mother physically assault his dad.
The son said during cross-examination by defense attorney Richard Gale that the fighting on the day his mother died was more contentious than normal.
Tyson Scott, 14, testified that his dad tried to hit his mom with their Dodge Durango a few years ago.
Closing arguments in the week-long trial are expected to begin Friday morning, at which time Judge David Mortensen will instruct the jury to consider "extreme emotional distress" as a mitigating factor during their deliberations.
Gale hopes the jury will convict Scott of the lesser crime of second-degree felony manslaughter, under the theory that Scott was not in his right mind at the time of the shooting.
On Wednesday, Tracy Scott testified how he stood in front of his wife and shot her.
"I snapped," Scott testified. "I just seen red. I went storming in [to the bedroom], she's laying on the bed, and she's got her cellphone [camera] pointed at me."
Scott testified that he reached down, grabbed a gun off the floor, cocked it and fired.
On the witness stand, Tracy Scott was emotional, his body racked with sobs. But his voice was flat and calm when he called dispatchers and told them his wife was dead.
Describing his 19-year marriage, Tracy Scott said: "We were two peas in a pod. ... We loved each other."
But Scott also said constant fights and bickering marred the relationship.
"It was bad," he said of their fights in the days before his wife's death. "It was get in your face, yell, scream at each other. Spit flying. It was a lot, lot worse [than it had ever been]."