A licensed engineer who has done work at the prison in upstate New York where two men escaped last weekend said the work of cutting through a cell wall and a steam pipe was a professional job.

Larry Jeffords, owner of Jeffords Steel and Engineering, tells The Associated Press that convicts David Sweat and Richard Matt were either very proficient with the tools they used — or they had help.

Jeffords' opinion is based on seeing photographs in the media.

Jeffords says cutting the cell wall and steel pipe would have taken about four hours and he's surprised nobody heard noise or saw sparks.

The killers cut through a steel wall, broke through bricks and crawled through a steam pipe before emerging through a manhole outside the prison grounds.