ARMSTRONG COUNTY — The Armstrong County District Attorney’s office will investigate the events surrounding the escape last week of an inmate who allegedly killed a woman shortly after fleeing the county’s jail.

District Attorney Scott Andreassi announced the investigation Tuesday, adding its purpose will be to determine the sequence of events leading up to Robert Crissman’s escape.

“It’s essential that we determine exactly what occurred the morning of July 30 that allowed inmate Robert Crissman to escape from the jail,” Andreassi said in a statement. “We will be examining all of the internal aspects and policies of the prison that led to Crissman’s escape — criteria for becoming a trustee, who determines trustee status, trustee duties, etc. ...”

Andreassi added his office will look into the supervision of trustees at the time of the escape.

Crissman, 38, of Templeton is charged with homicide, escaping prison, aggravated assault of a police officer, and theft of a gun and two trucks following the 26-hour manhunt that began after he walked out of a work-release program about 6:30 a.m. Thursday. Officials said Crissman walked out an unlocked door to get food from a delivery truck and never came back.

Police believe Crissman fled to the nearby home of Tammy Long, a friend of his, then allegedly strangled and beat her to death before stealing her pickup truck.

Crissman was arrested in Boggs Township the following morning after a police pursuit.

Officials said Crissman, who was in jail for violating probation on a drug charge, was trusted by the prison staff. Crissman’s criminal history includes multiple counts of theft, trespassing, drug possession and driving under the influence of alcohol, but no violent crimes.

Andreassi said he expects a report to be issued following the investigation.

“It is further anticipated that recommendations will be presented to the Prison Board and the Board of Commissioners at the conclusion,” Andreassi said. “Accountability demands that this investigation occur.”

The investigation will be headed by Assistant District Attorney Katie Charlton, who will be assisted by county detectives Paul Rearick, Franklin Roofner, Robin Davis and Charles Edwards.

Crissman now is in Butler County Prison.