Reacting to an ABC News investigation into theft by Transportation Security Administration officers, Senator Charles Schumer (D-New York) today called on the agency to do random sting operations on its employees "to test whether TSA agents are acting in a trustworthy manner to protect passenger property."

Schumer's request came in a letter to TSA head John Pistole and also proposed that the TSA randomly screen its employees at the end of the work day.

"Most TSA agents are very good, hard-working and conscientious, but there are a few bad apples that spoil the bunch," Schumer told ABC News today. "We have to find them."

Last week an ABC News investigation revealed that 381 TSA officers have been fired since the TSA was formed a decade ago for allegedly stealing from passengers. As part of the investigation, ABC News tracked an iPad that was purposefully left behind at an airport security checkpoint to the home of a TSA agent who was later fired for the alleged theft.

Another former TSA employee, Pythias Brown, served three years in prison for theft and said he stole approximately $800,000 worth of cash and merchandise from travelers before he was caught.

"It was very commonplace, very," Brown told ABC News. "It was very convenient to steal... [TSA agents] didn't think it was okay, but they did it and said, 'I don't care. They ain't paying me. They're treating me wrong.' But when people started seeing they could profit off of it, then it became massive."

In response to ABC News' original report, the TSA provided a statement that said it has a "zero tolerance" policy towards theft and that the number of officers fired "represents less than one-half of one percent of officers that have been employed" by the TSA.

The agency has conducted internal sting operations in the past after allegations of wrongdoing and has caught some officers red-handed, according to court documents.

The TSA Office of Inspection and the Department of Homeland Security Office of the Inspector General conducted a joint undercover operation at the Kona International Airport in Hawaii on March 11, 2011 "in response to numerous allegations that KOA Lead Transportation Security Officer... Dawn Nikole Keka, was suspected of stealing cash from Japanese travelers passing through her security lane," a criminal complaint said.

An undercover special agent of Japanese heritage placed 13 $100 U.S. bills in an orange wallet, and then placed the wallet in a Hello Kitty backpack and went through Keka's checkpoint screening.

Immediately upon leaving the checkpoint, the undercover special agent examined the contents of the backpack and discovered she was $200 short, the documents said. Another special agent asked Keka to empty her pockets and she produced two $100 bills. The agents matched the serial numbers of the two bills to ones the undercover special agent had placed in the backpack.

Keka ended up pleading guilty to one count of theft and was sentenced to two months in prison.

Schumer told ABC News that such operations should not just be conducted in response to reported wrongdoing, but randomly to keep all TSA agents honest.

"The TSA has a huge job, but when it comes to the security and safety of people's valuables, which they entrust to the TSA when they put them on the conveyor belt and go through the inspection, [TSA officials] have to be very, very careful and very, very vigilant," Schumer said. "Thus far they haven't done enough and could be doing more."

In response to Schumer's letter, the TSA told ABC News in a statement that "ensuring the safety of travelers through a professional workforce is of the highest priority for the TSA."

"TSA takes allegations of misconduct seriously and will take appropriate corrective action as warranted," the statement said.