McStay family murders: Mother of Joseph McStay testifies in Charles Merritt trial

SAN BERNARDINO, Calif. (KABC) -- In emotional testimony, the mother of Joseph McStay took the witness stand and recalled the moment she learned the remains of her son, his wife, and their boys, ages 4 and 3, had been found in 2013.

Susan Blake was the first witness called to the stand in the murder trial of Charles "Chase" Merritt, accused of killing the McStay family in 2010.

"He told me they found their bodies and they were.... they were dead all of them. I fell to the ground," Blake testified. "I kept saying it can't be. I asked him about the little guys and they told me that they were also gone."

The McStay family disappeared in 2010 without a trace from their Fallbrook home. Three years later, their remains were discovered in two shallow graves in the High Desert. Blake visited the site six months later.

"Me and my friend went to see the four crosses, and I just dropped to my knees. Because it shouldn't be, it shouldn't be. It's just such a shock to see that. I'll never go back to that spot," said Blake.

During her testimony Blake shed light on her son's business and his business partners in the days and months following his disappearance.

She recalled for the prosecution a heated argument Merritt got into with McStay's other business partner, Dan Kavanaugh. She told the courtroom Merritt was upset Kavanaugh wouldn't give him money from the business.

"They were yelling big time at each other, arguing and Dan was just not going to budge. It was scary, I literally walked out and said, 'If my son loses his business, so be it. I need to find my family.'"

Blake also testified she wrote nearly $5,000 in checks to Merritt.

"He asked for funds to keep the business going. At the time, I would do anything to help my son because I'm probably not in my right mind anyways at that time," said Blake.

Under cross examination defense attorney Rajan Maline tried to poke holes in the prosecution's financial motive for the killing.

Maline repeatedly asked Blake if she knew it was Kavanaugh and not Merritt who received money from a major project.

The prosecution objected several times to the line of questioning calling it out of line.

Blake did testify her son wants to downgrade his business and buy Kavanaugh out. She said he wanted to buy a warehouse and use more local welders.

But she told Maline he was incorrect about her son wanting to keep Merritt. She testified McStay told her he wanted to cut ties with Merritt who had a gambling problem and it was costing him money.

Blake's testimony wrapped up in the late afternoon. Her son, Michael McStay took the stand afterward. He wiped away tears as he stated Joseph was his only sibling and older brother he looked up to. The trial will resume Wednesday morning.