(CNN) -- Convicted serial killer Anthony Sowell walked jurors through his life as he testified Monday in the sentencing phase of his case, apologizing to families of his victims but offering no explanation for his actions.
"I'm sorry, I know it might not sound like much, but I truly am sorry from the bottom of my heart," Sowell told the jury and victims' relatives gathering in a Cuyahoga County, Ohio, courtroom.
Jurors on July 22 convicted Sowell of 11 counts of aggravated murder and more than 70 other charges, including abusing corpses and kidnapping.
Prosecutors are seeking the death penalty. If jurors decide to recommend that Sowell die for his crimes, the judge can overrule that recommendation and impose a life sentence. But if jurors decide to spare Sowell's life, the judge cannot impose a death sentence, according to Cuyahoga County court administrator Gregory Popovich.
As part of the sentencing phase, and in addition to testimony from prosecution and defense witnesses, Sowell was able to make a statement on his own behalf without being under oath or facing cross-examination from prosecutors,
Visibly agitated and occasionally tearful during his remarks Monday, Sowell maintained a candid banter with members of his defense team as he recounted claims of childhood abuse -- both physical and sexual.
Sowell said his childhood "was like a war," with his mother and grandmother constantly arguing, yelling and "whopping" the children.
He said the lack of nurturing in his home made him unable to stand physical contact or any signs of affection.
Sowell said he sought an escape and joined the Marines. He said he married and the couple had a daughter, but that his wife "was touchy-feely" and he never got used to the physical contact. Eventually their relationship dissolved and in 1985, Sowell began a 15-year sentence for attempted rape.
After his release from jail, Sowell said, his health began to fail.
Sowell said in 2007, he suffered a major heart attack and began hearing voices.
He did not elaborate on the crimes for which he was convicted.
"I don't know what happened, it's not typical of me," Sowell said. "I can't explain it and I know it's not a lot, but it's all I can give."
Sowell's convictions ended a saga that began in October 2009 with the discovery of the first two victims' remains inside Sowell's home. He eventually was accused of killing at least 11 women ranging in age from 25 to 52.