Two top Republican lawmakers said Thursday that newly-released documents show yet another gun connected to the botched Operation Fast and Furious emerged at a crime scene --- this time at a shooting in Arizona.

Sen. Chuck Grassley, R-Iowa, and House Oversight and Government Reform Committee Chairman Darrell Issa, R-Calif., said in a letter Thursday to Deputy Attorney General James Cole they are demanding the Justice Department “be forthcoming” about the 2013 incident, which happened at an apartment complex in Phoenix. In unrelated news, Cole announced Thursday he plans to step down from his position as the department’s No. 2 official.

“This lack of transparency about the consequences of Fast and Furious undermines public confidence in law enforcement and gives the impression that the department is still seeking to suppress information and limit its exposure to public scrutiny,” the lawmakers said.

The Department of Justice did not respond to a request for comment from FoxNews.com.

According to the lawmakers, two people were wounded in the shooting at the complex in July 2013. There were multiple shots fired at an apartment in the building, and soon after the shooting a car fled the scene. The driver of the car then crashed into a fence and several people were seen running from the vehicle. Four people were later arrested in the shooting and the arrests were reportedly connected to a drug trafficking probe, according to the lawmakers. 

The lawmakers state that after Phoenix police officers arrived they found an assault rifle in the vehicle, and later connected the weapon to Fast and Furious.

Grassley and Issa said they were able to confirm the incident through documents obtained by conservative watchdog group Judicial Watch as part of a request it made under Arizona’s open records law.

The lawmakers said the Phoenix Police Department report on the incident states that the weapon was traced the day it was recovered. However, the lawmakers said “the department did not provide any notice to the Congress or the public about this gun.”

“The refusal to respond to our standing requests for this information effectively hides the connection between crimes like this and Operation Fast and Furious,” the lawmakers said. “Unless the information becomes available some other way, the public would never know.”

The president of Judicial Watch, a, said in a statement Thursday that the new information shows the “Obama cover-up of Fast and Furious is ongoing.”

“Eric Holder’s Department of Justice is a mess,” Tom Fitton said. “It has endangered the public and is engaged in an ongoing cover-up of its insanely reckless Fast and Furious gun-running operation.”

During Operation Fast and Furious, federal agents permitted illicitly purchased weapons to be transported unimpeded in a failed effort to track them to high-level arms traffickers.

Federal agents then lost control of some 2,000 weapons and many of them wound up at crime scenes in Mexico and the U.S. Two of the guns were found at the scene of the December 2010 slaying of border agent Brian Terry near the Arizona border city of Nogales.

The Associated Press contributed to this report.