Serial killer Anthony Sowell breaks down at sentencing

(CBS/WOIO/AP) CLEVELAND, Ohio - There were tears from Ohio serial killer Anthony Sowell at his sentencing hearing Monday as a psychiatrist described his dysfunctional childhood.

Pictures: Anthony Sowell's alleged victims

Defense attorneys are trying to get the life of 51- year-old Anthony Sowell spared. They say the ex-Marine doesn't deserve capital punishment because he suffers from post-traumatic stress disorder and other mental illnesses. Sowell was found guilty last month of murdering eleven women and burying their bodies in and around his Cleveland home.

The first witness on the stand was Dr. Dale Watson, a neuropsychologist. He requested to not be filmed, despite being paid by taxpayers. Watson said Sowell has left and right brain dysfunction. He then described Sowell's dysfunctional childhood, at which point Sowell became emotional. The serial killer was seen wiping tears from his face when the doctor said Sowell did not have "one friend" as a youngster. During one session, Watson said Sowell told him that the voice he heard in his head had a name. He called it "Marty."

Watson also testified that Sowell's IQ, mental-processing speed and handling of spelling, puzzle and drawing tests rank him low compared to other people. He says the dysfunction may have been caused by a heart attack which can affect processing speed by reducing oxygen to the brain.

During the mitigation phase of the trial, the defense is expected to call up to 28 witnesses. The witnesses will include family members and persons familiar with the defendant, as well as experts retained by defense counsel. Sowell's attorney, John Parker, confirmed that the serial killer will testify on his own behalf in an effort to be spared the death penalty, reports CBS affiliate WOIO.

It is expected that the defendant's case will take 4 to 5 days to present. The state anticipates calling two to three witnesses in rebuttal.