Story highlights Surveillance video shows would-be bank robbers dressed in head-to-toe aluminum foil

Police speculate they thought the alarm system wouldn't be tripped

They left empty-handed before police arrived, possibly warned by lookouts

(CNN) Two would-be robbers left a shiny impression on police in southern Brazil, when they chose an unusual form of camouflage during an attempted bank robbery: head-to-toe aluminum foil.

According to Santa Catarina military police, the suspects were most likely trying to foil the alarm of the Praia Grande branch of the Banco do Brasil late Saturday when they chose the metal outfits.

What they failed to notice were the internal security cameras, which were capturing their every move in a centralized surveillance office.

"They broke down one of the walls and thought the detectors from the alarm would not notice them," Santa Catarina military police spokesman Maj. Cristian Dimitri told CNN. "When the bank's central monitoring system saw them on the screen, they called the police immediately."

Screen grabs from the closed circuit footage showed two men crawling on the ground in the improvised aluminum suits, near the bank's main safe.

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