The first witness was Patrick Clancy, her former husband, who found the children's bodies after returning home on the day of the killings.
Arizona detective John Byrd has been arrested and charged in his wife's death after he allegedly strangled her and locked her body in their bedroom before fleeing the scene.
She confessed and told police she did not want her son to grow up with the family's financial problems.
"I mean, the neighbors did a really good job and possibly saved her life," said Deputy Chief Mike Packer.
Her father posted a message on Twitter, writing that she "has inspired so many to live, travel and leave unhealthy relationships."
"No one was in the bedroom with her when this happened, so there was no one there to save her."