A would-be robber of the bank where he worked pleaded guilty Tuesday to a heist that quickly went awry.

Dwayne Roberts, 31, faces up to 10 years in prison under his plea agreement with prosecutors. He pleaded guilty to arson and theft in Marion Superior Court and will be sentenced Dec. 15.

In May, Roberts was an assistant manager at a Fifth Third Bank branch on the Northwestside when he tried to conceal his ongoing theft of cash totaling about $200,000, according to a prosecutor.

Roberts sent employees home, set fire to a box of money inside the vault and sealed it — realizing only then that the keys to his truck were inside. He called 911 to report the fire at the bank branch, 5692 Georgetown Road.

The plea deal requires restitution of $198,500 for stolen money and $20,000 for repairs and cleanup.