CHICAGO (AP) — A convicted bank robber has pleaded guilty to escaping from a high-rise Chicago lockup with a cellmate last year.

Kenneth Conley changed his plea in U.S. District Court Monday after negotiating a plea agreement with prosecutors.

The 39-year-old Tinley Park man is already serving a 20-year sentence for bank robbery. A judge could hand Conley as much as five additional years behind bars when he’s sentenced for the escape on Feb. 6.

Conley and Jose Banks scaled down 17 stories of the Metropolitan Correctional Center using a rope fashioned from bed sheets and dental floss. Banks was soon caught. But police stopped Conley disguised as an old man in a suburb only weeks later.

Banks already faced up to 80 years for bank robbery, so authorities dropped the escape charge.

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