The heart of the state's case is testimony from friends, relatives, and acquaintances of the two women about things they allegedly told them about Drew Peterson. Such testimony, called hearsay, isn't usually allowed in court, but Illinois passed a law in 2008, dubbed "Drew's Law," that allowed it to be introduced at trials under rare circumstances.
In his more than hour-long closing, prosecutor Chris Koch went through more than half a dozen hearsay statements, including witnesses who testified Savio told them her husband repeatedly warned her he could kill her and make her death look accidental.
As he began his remarks Koch walked up to the defense table, pointed his finger at Peterson and boomed, "It is clear this man killed Kathleen Savio."
Punching his fist into his palm for emphasis, Koch said Peterson slipped into his estranged wife's suburban Chicago home - just a few blocks from his new house - in the early morning hours before March 1, 2004.
"He went into that house, pushed her down, held her down until she inhaled fluid and drowned," said Koch.
Defense attorney Joel Lopez told jurors that when they deliberate, they are required to hear a voice whispering to each of them that Peterson is innocent. He said they can't conclude Peterson is guilty unless the evidence is overwhelming and compelling.
Lopez constantly doubled back to his central argument: The state hadn't even proved Savio's death was a murder.
"The framers of the Constitution would barf on this evidence," said Lopez.