The demolition operator in the Philadelphia building collapse that killed six people was a felon with a lengthy rap sheet who was high on marijuana and painkillers at the time, officials say.

Police are still looking for 42-year-old Sean Benschop, whose rap sheet spans 11 arrests in nine years for drugs, theft, and weapons possession charges. The AP reports that Benschop, who also goes by the name Kary Roberts, served time on drug trafficking convictions in the 90's, and was most recently arrested in January, 2012 for aggravated assault. That case was dismissed for lack of evidence.

City officials say that witness statements, toxicology reports, and evidence taken at the scene show that Benschop was high on marijuana and possibly codeine as he operated the demolition equipment on Wednesday. Benschop's blood and urine were tested about two hours after the collapse, and CBS reports that police officers say Benschop was speaking in an extremely slow and quiet manner, "as if he were whispering." He allegedly told investigators he was taking painkillers after cutting his finger.

The building Benschop was demolishing collapsed on top of a nearby Salvation Army store, killing two employees and four customers. It was the first day of work for one of the employees killed in the collapse, and thirteen other people were injured when the building fell.

There may also be charges coming to the demolition contractor, Griffin Campbell. Video of the scene shows that the sidewalk was left open to pedestrians as bricks fell from the building shortly before the collapse, and an attorney for one of the injured victims says there were multiple federal safety violations.

Currently, Philadelphia does not require inspections during demolitions, and the state of Pennsylvania does not license demolition contractors. Carlton Williams, the head of the Philadelphia's Department of Licenses and Inspections, told the AP that demolition contractors are not required to show proficiency, but that a pre-inspection of the building revealed no issues. Officials inspected four of Campbell's other demolition sites and found violations at two of them. Those projects have been suspended.

Police raided Benschop's home Friday, taking two computers and other evidence, but they are still trying to locate Benschop. When they do, he will be charged with six counts of involuntary manslaughter and six counts of risking catastrophe, among other charges.

[The Washington Post]