No charges have been filed in the 6:44 a.m. shooting.
District Attorney John F. Nelson said he met with investigating officer Trooper Anthony Manetta on Tuesday. He said authorities were waiting for results of forensic tests before deciding whether any criminal charges will be filed.
"We're trying to get as much information as we can," Nelson said. "I don't think it's going to be a long process."
Attempts to contact Atkinson and Pittman on Tuesday were unsuccessful.
Autopsy results confirmed that Barbour, 34, died of multiple gunshot wounds, police said. Franklin County Coroner Kenneth L. Peiffer Jr. and police refused to reveal the number of times Barbour had been shot.
Police would not say whether Barbour was armed and would not describe the weapon with which he was shot.
Atkinson and Pittman were at home alone at the time of the incident, police said.
Pittman's and Barbour's three children were staying at their grandmother's Chambersburg home.
Pittman, 26, a native of Chambersburg, had filed a protection from abuse order against Barbour in August after he was charged with harassment and simple assault, according to Franklin County Court records.
The order prohibited Barbour from having contact with Pittman and from harassing her and her relatives.
Barbour was sentenced to 90 days in Franklin County Prison in October 1996 for violating the protection order three times, court records said.
After his release from jail in January, Barbour violated the order twice, court records said.
Barbour was charged with indirect criminal contempt for the violations, but Pittman dropped the order and the charge three weeks ago, court records said.
Pittman also asked the Franklin County District Attorney's office to drop the harassment and assault charges.