Jurors were instructed to disregard the fact that executions are currently on hold in California due to a moratorium imposed by the governor.
The prosecution portrayed the 43-year-old repairman as a psychopath who posed as a nice guy.
"He doesn't give a damn about anyone. That is Michael Gargiulo," said prosecutor Garrett Dameron.
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Prosecutors urged the death penalty, pointing to his series of choices to brutalize his victims.
Gargiulo was married, had a family, and knew the difference between right and wrong as demonstrated by his techniques to hide evidence.
The father of two ingratiated himself to young women who lived nearby, then returned with a knife to kill and mutilate them.
The number of wounds were displayed from the coroner's report. Ashley Ellerin, a former girlfriend of actor Ashton Kutcher, was stabbed 47 times. Maria Bruno, a mother of four, was stabbed 17 times.
The destruction of the victims' families punctuated the prosecution's points.
"Ashley Ellerin now sits in an urn on their mantle thanks to Michael Gargiulo," stated Dameron.
The defense urged sympathy for Gargiulo's son who testified he still needs his dad and claims that while Gargiulo is sane, that he suffers from a personality disorder.
"I think we lose something of our humanity if we execute the mentally ill," argued defense attorney Daniel Nardoni.
Prosecutors say the defendant understood what he was doing and used gloves and booties over his shoes to hide his trail. He was caught after he was cut during a 2008 attack in Santa Monica. His DNA linked him to the 1993 murder of Gelnview teenager Trisha Pacaccio.
Gargiulo has been charged with killing Pacaccio 26 years ago, in 1993 and will be extradited to Illinois to face trial after his penalty is decided in California.