Attention wannabe robbers: Avoid IRS agents trained in the use of firearms.

Three alleged criminals found this out the hard way when two of them ended up shot after trying to rob a woman unloading her car in the parking area of her San Francisco home.

The failed robbery attempt took place near midnight Aug. 4 in the Bayview neighborhood, the San Francisco Examiner reported. Police said the 36-year-old agent had just returned home from work when one suspect raised a shotgun, pointed it at her chest and demanded money and property.

"Obviously," police told the newspaper, "they had no idea that they had just decided to rob an armed law enforcement officer."

Using "her many years of training," police said, she drew her gun, identified herself as a federal agent and fired. As all three ran away, she called San Francisco police.

Police found one suspect hiding under a house, needing medical treatment for a gunshot wound to the torso. A second suspect was found inside a nearby house, uninjured, the newspaper reported. "The third suspect had also suffered a gunshot wound but managed to run home and get a relative to drive him to an emergency room," police said. "Hoping to elude capture, he chose a hospital far from the Bayview." The suspect was shot in the leg. The police found the suspect's loaded shotgun inside the car parked at the hospital.

The injured suspects are expected to recover. All three were arrested and charged with robbery. Police spokesman Sergeant Troy Dangerfield said the man with the shotgun will likely face stiffer charges, according to the San Francisco Weekly.

The agent, who works with the criminal investigation division in Oakland, has been placed on paid leave pending investigations by San Francisco police, the district attorney's office and the IRS, the San Francisco Chronicle reported.

Related article:

• Armed and dangerous: Sharp-shooting IRS agent guns down would-be robber