The trial for the Delhi father accused of gunning down his adult son during a heated argument over a chainsaw got underway this week.

Daniel McDonald, 68, is facing a first-degree murder charge for the shooting death of his 46-year-old son Donald McDonald on April 9, 2011.

The key consideration the jury will be asked to weigh is if Daniel McDonald shot his son to death while in a drunken rage over a broken chainsaw, as the Merced County District Attorney’s Office contends, or if Daniel McDonald was a victim of ongoing elder abuse at the hands of his son and was forced to defend himself with a rifle, as defense attorney Frank Carson presented it to the jury.

There has never been any doubt that Daniel McDonald fired the fatal shot that killed his son. On the 911 call Daniel McDonald can be heard in the background admitting to the shooting and when Merced County Sheriff’s deputies arrived at the Griffith Avenue residence they found Daniel McDonald still clutching the smoking rifle.

Donald McDonald’s wife Sandra McDonald and friend Curtis Tipton were both present at the Delhi residence the night of the shooting and were called as witnesses by Deputy District Attorney Thomas Min.

Tipton testified the two men were arguing about a chainsaw and that the argument turned violent after Daniel McDonald told Sandra McDonald to “shut up.”

Daniel McDonald went into his home and tried to lock the three out. Father and son tussled at the front door, but Daniel McDonald was eventually able to bolt the door shut.

Sandra McDonald testified Donald McDonald climbed through their bedroom window and was in the living room when a single shot was fired.

Sandra McDonald said she made her way into the home and found Donald McDonald lying on the floor bleeding.

“I tried to close his eyes for him and told him I loved him and please don’t die,” Sandra McDonald testified.

The majority of the testimony has been from Sandra McDonald, whose recollection has gotten more and more muddled over the three days, including one full day of intense cross-examination by Carson.

Carson is working to have part or all of Sandra McDonald’s testimony impeached, claiming she has not been truthful in her testimony. Carson has been trying to introduce Sandra McDonald’s past run-ins with law enforcement, including at least two incarcerations. But his attempts have been stymied by Merced County Superior Court Judge Ronald Hansen’s rulings.

The attempts have prompted terse exchanges between the two attorneys outside the presence of the jury and earned them admonishments from the judge.

Daniel McDonald remains in custody at the Merced County Jail. His trial is scheduled to resume Tuesday with Sandra McDonald taking the stand again.