A 73-year-old man told authorities he robbed a Fort Pierce bank because he's on a fixed income and had gambled his money away on horses and Texas hold `em.

[PHOTOS:   Underwear robbery suspect caught]

St. Lucie County Sheriff's officials say he put black underwear over his face and took a loaded shotgun into a TD Bank on Wednesday.

Deputies say the man ordered two bank employees out of their offices. He told them to go to the teller counter, where he placed a Walmart bag on the counter and ordered them to fill it with cash, deputies say.

He ordered employees to the ground and told them to count to 100, according to deputies.

A bank robbery detection device helped deputies track him down. He faces charges of armed robbery and aggravated battery with a weapon.