Mollie Shouse breaks down during murder trial Tuesday

LOUISVILLE, Ky. (WDRB) -- Was it a mistake or murder when a child died after being left in a hot car?

That was the question at the emotional Mollie Shouse murder trial Tuesday afternoon.

The car: that is exactly where Susan Boyd found her grandson last May. She went to her daughter Mollie Shouse's apartment after her daughter did not answer several phone calls.

Boyd says that while her grandson was suffering in the car, Shouse was sleeping.

Shouse is charged with murder for the death of her 2-year-old son, Kenton Brown, who was found in her hot car in his car seat. Investigators say he had been left there for several hours and died.

"He was a healthy happy boy," said Boyd, adding that he was, "the light of our lives."

Defense Attorney Patty Echsner argued that Shouse did not intentionally kill her son, but prosecutors say the death was intentional and Shouse made the choice to murder her son. Prosecutor Erin White called her, "cool and calculating."

Shouse also faces drug charges after drugs were found in her apartment. A firefighter who was first on the scene says Shouse appeared to be high on drugs that day.

"I knew Mollie smoked marijuana, but never saw her do any pills," Boyd said.

Boyd says she was subpoenaed to be a prosecution witness. She says she loves her daughter and will do anything to help her.

"Mollie took excellent care of Kenton," she said. "She was a good mom."

A neighbor who was at the scene, recalls Shouse's reaction to her son's death. Scott Dennis says, "She seemed to be in a state of distress, shock, under the influence. She said I guess this is how a child looks after it's dead."

Shouse's attorney says she made a mistake that she'll have to live with for the rest of her life.