(CNN) -- Jurors will continue deliberations on Friday on whether Joshua Komisarjevsky will be put to death for his role in a deadly Connecticut home invasion in 2007.
The jury has been unable to reach a decision after four days of discussing whether Komisarjevsky -- the second of two men convicted in the home invasion -- will be executed or spend the rest of his life in prison.
Komisarjevsky was convicted in October on 17 charges, including three counts of murder, four counts of kidnapping, and counts of burglary, arson and assault in the deaths of Jennifer Hawke-Petit and her daughters, Hayley Petit, 17, and Michaela Petit, 11.
The sentencing phase of his trial began in late October. The defense has argued Komisarjevsky had no history of violence and adjusted well to prison life. He was abused as a child and was committed to a mental hospital for depression, attorney Jeremiah Donovan has said.
Steven Hayes, the first defendant to stand trial in the case, was sentenced to death after a jury convicted him on 16 of 17 charges last year.
Prosecutors argued that Hayes and Komisarjevsky went into the Petit home, beat and tied up William Petit, raped and strangled his wife, molested one of their daughters and set the house on fire before attempting to flee.
The two daughters, who were both tied to their beds, died of smoke inhalation, while William Petit managed to escape.
CNN's Brian Vitagliano contributed to this report.