A defense lawyer says a man charged with killing a Virginia police officer on her first shift is mentally impaired as a result of two tours in Iraq.

Ronald Hamilton is charged with capital murder in the Feb. 27 shooting death of Prince William County police officer Ashley Guindon, who was working her first shift as a sworn officer.

At a pretrial hearing Tuesday in Manassas, Hamilton's lawyer, Ed Ungvarsky, said he expects Hamilton's state of mind to be a major issue going forward. Hamilton is a 32-year-old Army staff sergeant from Woodbridge.

Prosecutors say Hamilton shot Guindon and two other police officers who responded when Hamilton's wife called 911 for help. Crystal Hamilton was found shot dead in her home. The other officers who were shot survived.