An interesting article from NY Times discussing many security lapses by the Clinton prison was published on Sunday 6/21. Here is a list of the lapses (compiled by Business Insider):
Nightly bed checks were not performed properly.
Underground tunnels, through which Sweat and Matt escaped, were not regularly inspected even though they used to be inspected once a week. One current officer said the last inspection he could recall was in October.
No one was inside two of the 35-foot-high watch towers on the south side of the prison, nearest to the manhole the prisoners fled out of. For years, they had not been staffed overnight but since the escape, the towers have been staffed around the clock.
Some security posts were no longer filled despite modest increases in personnel.
In recent years officers stopped patrolling the catwalk behind the cells where it is believed the two escaped murderers found some of the tools they used to escape.
The inmates may have found tools left by contractors on the catwalk.
Although forbidden by prison rules except when using the toilet, putting sheets across cell bars to obstruct viewing was frequently allowed.
The prison does not have video cameras on the cell blocks.
For those interested in this story, the full NYT article is worth checking out.