U.S. Sen. Kirsten Gillibrand says she will be backing a bill to crack down on corrupt gun runners and dealers.

Nearly 90 percent of firearms used for crimes in the five boroughs are bought and sold out of state. Most of the guns used for crimes are illegal as well, according to Gilibrand, who will introduce her Gun Trafficking Prevention Act later this week.

Recently, State Attorney General Eric Schneidermann announced that his office plans to crackdown on illegal gun distribution in the state. In fact, a probe conducted by his office revealed that many gun sellers disregard state mandated background checks, according to the Associated Press. The probe also revealed loopholes in current gun laws. An individual gun seller can is legally accountable for the guns they sell, but not a gun show operator.

The Attorney General's critical investigation shows just how easy it is for guns to end up in the hands of dangerous people, Gillibrand said in a statement, according to the Associated Press. By cracking down on gun dealers who blatantly disobey the law as well as illegal gun traffickers and their vast criminal networks, we can reduce gun violence and keep our families and neighborhoods safe.

The proposed legislation toughens penalties for illegal gun sales. Traffickers could face nearly 20 years in prisons. The head of gun trafficking operations could receive an additional sentence of five consecutive prison terms, with penalties increasing with the number of guns illegally sold.