MEMPHIS, Tenn. --- Postal Police officers say they want to help curb crime but are limited. The union president believes a recent robbery could lead to even more problems. Frank Albergo leads the National Postal Police Officers Union. "We can make a difference in a city where there are Postal Police like Memphis," Albergo said. Postal Police officers are the uniformed division of the postal service stationed at major postal facilities as security. They're different from postal inspectors who investigate mail-related crime. Postal carrier robbed at apartments; $150K reward offered Earlier this month, someone robbed a letter carrier in an apartment complex in southeast Memphis. A picture on a reward poster shows the suspect pointing a gun at a mail truck. He reportedly got away in a black Nissan Altima but we don't know what he took. Albergo warns anyone living in the 38119 zip code where this theft happened their mail may be compromised. He says this is due to what's called an arrow key that letter carriers use to deliver mail. "Once you get an arrow key you have access to all the blue collection boxes, the apartment panels," Albergo said. "It's a window into check fraud, banking fraud, identity theft. Do not use blue collection boxes, do not use blue collection boxes at all. Pick up your mail immediately when it's delivered." The former letter carrier says this is where postal officers can and want to make a difference. Right now they can't investigate crimes outside of USPS property, but he says they want to expand their scope. "We have the exact same training as postal inspectors," Albergo said. Albergo says right now the union is still fighting legal battles to be able to investigate mail thefts like the one earlier this month. We reached out to the U.S. Postal Service looking for answers but have not heard back at this time. The battle continues in Congress, where there's a bill that would give postal officers more authority.