Officials are claiming Sean Benschop was “high” on marijuana and possibly codeine while operating the demolition equipment during last week’s Philadelphia building collapse that killed six people and injured 13 others. Benschop has been missing since Wednesday, when the building collapsed on top of a Salvation Army store, killing two workers and four customers. Witness statements, toxicology reports, and evidence taken at the scene show Benschop, 42, was high at the time, and he admitted to investigators that he was taking painkillers due to a cut finger. His blood and urine were tested two hours after the collapse and CBS reported that police officers said he was speaking in an extremely slow and quiet manner, “as if he were whispering.” Benschop, who also goes by the name Kary Roberts, has been arrested 11 times in the last nine years on drugs, theft and weapons charges. He was most recently arrested in January 2012 for aggravated assault, but the case was tossed out due to lack of evidence. Police raided Benschop’s home on Friday to seize computers and other evidence, but still have no leads as to his whereabouts. Once he’s caught, the charges against him will include six counts of involuntary manslaughter and six counts of risking catastrophe. The demolition contractor, Griffin Campbell, could also be facing charges. An attorney for one of the injured victims claims there were multiple federal safety violations and officials also found violations at two of his four other demolition sites.