He described in graphic detail how he beat the father with a baseball bat.
Then how he sexually assaulted the youngest daughter, just 11 years old, moments before she was set on fire.
The tapes were released Monday, but played in open court last week.
It is so hard to hear that as Komisarjevsky called Michaela Petit by her nickname and described sexually assaulting her, the judge had to yell stop, and let disturbed jurors go home for the day.
For two long hours, Joshua Komisarjevsky told investigators the whole sordid story.
With zero emotion in his voice, he described how a robbery spiraled into a sexual assault, rape arson, and murder, pointing the finger at his partner in crime, Steven Hayes.
"I'm not killing anyone. That's not how it's going down. We were simply here for the money. Get in and get out," the audio tape played.
The audio is from a taped confession with Cheshire Police in July 2007, played for jurors last week.
Komisarjevsky told investigators how he saw Jennifer Hawk-Petit at the grocery store and randomly chose to rob them.
After following them home, Komisarjevsky admitted to beating Dr. William with a baseball bat.
"I hit him in the head with a baseball bat. He let out this, this unearthly scream. Uh, I couldn't take his screaming," Komisarjevsky said on the tape.
But most disturbing, is when he described how a conversation about summer plans ended in the sexually assault of 11-year-old Micheala Petit.
Det. Vitello: "So you cut her clothes off for that purpose?"
Det. Vitello: "Okay, did you take pictures of her?"
Komisarjevsky: "Uh, I did yes."
Det. Vitello: "With?"
Komisarjevsky: "Uh, with my camera phone."
Komisarjevsky said he took the explicit photos of Micheala as insurance, just in case Hawk-Petit didn't return with the cash.
In court, the medical examiner testified that Hawk-Petit and her daughters died within a few minutes of smoke inhalation.
When jurors were shown autopsy photos, Dr. William Petit had to leave.