A confessed burglar said he "lost control" while beating Dr. William Petit with a bat before going on to murder Petit's wife and two daughters and admitted he started to "enjoy it," according to his journal entries read in court today.
The 43 pages written by Joshua Komisarjevsky were presented in the penalty phase of Steven Hayes' murder trial. Hayes was convicted of breaking into a Cheshire, Conn., home in 2007 and murdering Jennifer Hawke-Petit and her two daughters Hayley, 17, and Michaela, 11. The mother and one of the girl's was also raped.
Komisarjevsky, 30, will go on trial for the murders later.
A jury is now hearing evidence to determine whether Hayes, 47, should be executed. The judge allowed the letters and diary to be presented to help the jury determine the culpability of each man and their "relative evil."
Hayes' lawyers hope the diary will show the jury that Komisarjevsky was the ringleader on the night of the Petit murders and spare Hayes the death penalty.
"I'm not an angel," Komisarjevsky wrote. "I've never claimed to be. The scars on my soul have forever defined me as different than others."
Komisarjevsky said that he "resented" the implication that he raped Michaela and wrote that he had "spared her that degree of demoralization." Admitting that he did in fact sexually assault her, Komisarjevsky wrote, "In a vulgar display of power, I ejaculated onto her."
"As for why? It was the accumulation of years of pent up aggression," he wrote.
Komisarjevsky admits in the journal to taking photos of Michaela after the assault, images he wrote that he planned to use to blackmail her parents.
"What I was not prepared for was my demons getting the better of me," he wrote.
Hayley was the fighter of the family, according to Komisarjevsky, who claimed the father was "passive" toward saving his family.
"If you don't want to defend your family, then take your chances with the criminal while police sit outside and follow protocol," wrote Komisarjevsky.
"Hayley is a fighter. She continually tried time and time again to free herself," he wrote. "Michaela was calm. Mrs. Petit's courage was, is, to be respected. She could have stayed inside the bank where she was safe."
In a cruel twist, Komisarjevsky scoffed at William Petit's escape the night of the attack. The father was bound in the basement, got free and ran to a neighbor's house to call for help. Before help arrived the house was engulfed in flames.
"Mr. Petit is a coward, he ran away when he felt his own life was threatened," Komisarjevsky wrote. "Time and time again I gave him the chance to save his family."
William Petit, who has attended every day of the the court hearings, sat stoicly through the accusation.
Turning some of the blame on Hayes, Komisarjevsky wrote, "When Steve took the life of Mrs. Petit, he took it to a whole new level."
"I am what I am and make no excuses," he wrote. "I am a criminal with a criminal's mind, and my anticipated death sentence will be a sentence of mercy."
The composition notebooks that contained Komisarjevsky's writings were discovered by Rafael Medina, a detective for the Connecticut State Police, who testified that he was alerted in July 2008 that Komisarjevsky was corresponding with author Brian McDonald, who wrote "In the Middle of the Night: The Shocking True Story of a Family Killed in Cold Blood" about the Petit murders.
Four journals were seized from Komisarjevsky's prison cell. McDonald deposited $100 into Komisarjevsky's prison bank account at least three times and the two men exchanged as many as 11 letters.
In his journals Komisarjevsky claims that once he started beating Dr. Petit it "released a leash too hard to rein back in."
"I was faced with the shocking realization that in some respects, I enjoy it," he wrote. "They were experiencing what I experience every day."
Komisarjevsky appears to question his actions, writing, "I am not proud of the outcome of July 23."
The journals also depict a sense of regret by Komisarjevsky, who writes, "Michaela, angel of my nightmares. My pain to yours does not compare. How could I have turned my back walking out that door knowing your fear and sorrow?"
"Michaela, Haley, Jennifer - forgive me please," he writes. "I am damned, take my life."
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Prosecutors dismissed Komisarjevsky's writings as figments of his imagination that depicted "the world according to Josh."
Parts of the letters written by Komisarjevsky read as how-to guide to burglary. He writes, "French doors are a pain in my a.. and not worth my time."
"I'm a burglar, everyone knows I'm a burglar," he boasts in the letters. "[I can] get into any building I put my mind to."
"If the house has kids or the neighborhood has a lot of play sets, the location of the bus stop is important," Komisarjevsky wrote. "I check to see if there is a neighborhood watch program."
"Every home has its own unique noises," he said. "I memorize these sounds and mimic them as I move through the house."
Komisarjevsky describes in the letters how he'd always wear black turtlenecks during robberies and would linger on the property he was targeting so he could catch a glimpse of the alarm code as the homeowner enters it. Then he comes back in the morning, "makes certain no one is home, and the burglary begins," he wrote.
"If you look like you belong, then you're invisible," he wrote.
After the burglaries, Komisarjevsky said he'd often go out, writing that he "likes strippers."
Earlier testimony focused on Hayes when a witness described the convicted rapist and killer as often being "vulgar" toward women and said he would shout crude remarks to women they passed on the street.
Philip Theed, a building contractor who briefly employed Hayes in 2007, was one several witnesses called to the stand by the defense lawyers in an attempt to spare the murderer's life.
Theed told the jury today during several long car rides with Hayes to and from work the conversation would turn to sex.
"He made comments that he particularly liked oral sex," said Theed, adding that it was, on occasion, "vulgar and rude."
Several times Hayes would yell at women working at the condos where they were doing construction in a "sexually suggestive way."
"He would just speak of his desires for women and liking oral sex and he had the hots for sort of Latino women who were working at the condos," said Theed.
Theed lent his car to Hayes in the days leading up the invasion of the Petit home in Cheshire, Conn.
The sentencing phase of Hayes' trial began Monday with the convict's lawyers asking the jury to have an "open mind" when it came to determining his punishment.
"You will learn that he has a long criminal history of being a burglar and a thief and a person who has for a long period of time in his life [had] a serious drug abuse addiction," public defender Patrick Culligan said. "You will also learn he could be a good worker ... he could be a likable person."
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The defense's first witness, former investigator D'Arcy Lovetere, said she got to know Hayes during her time with the public defender's office in his hometown and described him as a "gentleman" and "motivated to work," who was always remorseful for his crimes.
"He wasn't the best criminal in the world for sure," Lovetere testified. "His addiction overtook him , but he just wasn't all that good as a criminal, I guess. He was a klutz."
"He was definitely a follower," she said.
And when she found out that Hayes, who once had a crush on her then-teenage daughter, Lovetere testified, "It knocked the wind out of me."
"I couldn't believe it," she said. "I just was shocked."
The defense also called witness Christiane Gehami , who owns the West Hartford restaurant Arugula where Hayes worked as a pantry chef in 2006, while he was living in a halfway house.
Hayes would often get rides homes from Gehami who said she found Hayes to be "funny" and added that he "got along" with the other employees.
"Nobody lasts in there if you don't get along," added Gehami.
Gehami told the court about a time when Hayes broke up an argument between her co-chef and another man.
"Basically what Steve was doing was protecting me from this guy," she said.
Gehami also provided of preview of the pending trial of Hayes' co-defendant Joshua Komisarjevsky. She said that Komisarjevsky sometimes came to the restaurant to "help with projects" and that she recalls thinking she was "looking at the devil" and denied his offer to work for her.
Komisarjevsky had "dead eyes," added Gehami.
The sentencing phase is expected to be concluded by Oct. 29.
Dr. William Petit, the sole survivor of his family's massacre, has been in the audience throughout the trial. Earlier this month Petit announced that he will not give a victim impact statement during the penalty phase.
In a statement, Petit cited what he considers to be a lack of clarity in Connecticut law regarding the reading of victim impact statements, saying it is not well-defined whether such a statement should be read by the victim himself or by the prosecutor and whether or not such a statement should be presented prior to or after the sentencing.
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Petit said he feared that "this lack of clarity" could be used by an appellate court to rule that a victim impact statement improperly influenced sentencing.
"I do not presently intend to seek to offer a victim impact statement in this case precisely because of my concerns that it could be used (wrongly) as a basis for appeal and possibly even a new sentencing trial," Petit said.
Together, prosecutors say, Hayes and Komisarjevsky ambushed the Petit family on a summer night after Komisarjevsky followed Hawke-Petit and Michaela home from a grocery store and targeted the family as wealthy.
The two intended to rob the family, but after finding little cash in the house they held the family captive for hours before driving Hawke-Petit to the bank to withdraw $15,000. Hawke-Petit was seen on the bank's surveillance system pleading with the teller to help her family.
Prosecutors alleged that Komisarjevsky raped Michaela, later forcing her to take a shower before tying her to her bed. During Hayes' trial, prosecutors argued that he raped Hawke-Petit before strangling her. As the two girls lay tied to their beds with Hawke-Petit dead on the lower floor of the house, Hayes and Komisarjevsky set fire to the house, prosecutors said, pouring gasoline on and around the girls' bed before fleeing.
ABC News' Sarah Netter contributed to this report.