An emergency worker testified Thursday about finding the body of a murdered 2-year-old boy in brush near a northeast Iowa pond and a first-aid kit that the boy's brother used to try to help him.

Jesup firefighter Shawn Even testified during an emotional opening day of testimony in the first-degree murder trial of Michelle Kehoe, 36, in Grundy County. The Coralville woman is accused of killing her son Seth and injuring another son, 7-year-old Sean, near Littleton on Oct. 26, 2008.

Kehoe's public defender, Andrea Dryer, has said she intends to use insanity and diminished capacity as a defense.

Prosecutors said she covered her sons' faces with duct tape before she slit their throats.

Even testified Seth's body was found near the passenger side of the family's van, parked near the pond. He said Sean was sitting with his knees to his chest inside the van. Even told jurors Sean had a cut on his neck.

"He said that's from his mom," Even said.

Next to Seth's body was a first-aid kit, Even said. Sean told him that it was "from him trying to help his brother," Even said.

A recorded interview Sean Kehoe did with a state trooper was played for the jury as Kehoe and family members listened.

"Your mommy is the one who hurt you?" said Trooper Jim Smith.

"Yes," Sean said.

Smith said Sean was in the family van at the time looking in the direction of Seth's body.

Paramedic Rebecca Smith testified that Sean Kehoe had a cut several inches long and a half-inch deep.

He was taken to Covenant Medical Center in Waterloo, where he told a Black Hawk County sheriff's deputy that his mother cut his throat.

Debra Hinde, who lives near the pond, testified that Kehoe came to her door about 7:30 a.m. on Oct. 27 with a cut on her neck and covered in blood.

"I opened the door and this person fell into my doorway," Hinde said.

Hinde testified that she called 911 as Kehoe crawled into her house. Kehoe later wrote two notes, one with her husband Gene's phone number and another that said, "A man killed my boys and tried to kill me."

Later she admitted to authorities that she cut her sons' throats after Sean told police what had happened.

Prosecutors said Michelle Kehoe began planning the killing up to two months before when she bought duct tape and a knife.

"Her elaborate and meticulous planning of the murder of her two children had thus began," said Andrew Prosser, an assistant state attorney general.

The trial was moved to Grundy County because of concerns she could not get a fair trial in Buchanan County.