Howard Holland, a special liaison for the Chester County, Pennsylvania, Prison Board, confirmed Cavalcante escaped Chester County Prison through an exercise yard, after he “crab-walked up a wall” and scaled a fence that had recently been re-topped with razor wire, following a different inmate’s escape from the same prison in May.

Cavalcante then ran across a roof and “pushed his way through” more razor wire in order to escape, Holland said.

Holland also said that officials in Pennsylvania had determined in May the new razor wire was “sufficient,” admitting those measures “should have been bolstered,” and that the prison is addressing its security measures, including by considering fully enclosing all outside exercise areas and installing more cameras.

A prison officer in the facility’s observation tower did not observe or report Cavalcante’s escape, and his absence was only discovered when inmates were counted later Thursday morning, Holland said—that guard has since been placed on administrative leave.

Cavalcante, who was convicted of first-degree murder in August and sentenced to life in prison, was sighted last in Pennsbury Township, south of the area where police had been searching, officials said in a press conference on Wednesday.