Celinez Nunez remembers the day she knew she would become a law-enforcement officer.

She was just eight years old and living in Logan Square.

On that day in 1983, she learned that gang members beat her older cousin to death with a nail-studded baseball bat.

Hector Sanchez was like her big brother. He combed her hair and took her to school every day.

His murder changed Nunez’s life.

“When this happened I said, ‘You know what? I want to go after these guys. I want to go after these gangbangers that cause havoc in our community.’ I never want anyone to go through what my family went through. For me it’s personal. It really is.”

Nunez went on to become an agent with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives. She held several high-profile positions supervising agents in Seattle and Puerto Rico.

And recently, the 41-year-old Northwest Side native landed her dream job. She was named the special agent in charge of the Chicago office of the ATF at a critical time for the agency because of the national focus on violence here.

In early January, President Donald Trump tweeted about the city’s struggle to reverse the total of more than 760 killings in 2016, the highest in decades.

“If Mayor can’t do it he must ask for federal help!” Trump wrote.

Later, Chicago Police Supt. Eddie Johnson responded that he’d welcome the help. The Chicago Police Department was more than willing to build on its partnership with ATF and other federal agencies, he said.

Chicago Police Supt. Eddie Johnson

Chicago Police Supt. Eddie Johnson has said he would welcome federal assistance in dealing with Chicago’s violence. | Sun-Times file photo

Sources have told the Chicago Sun-Times that dozens of new ATF agents are being sent to Chicago to fight the gun violence here.

Nunez wouldn’t discuss how many additional agents the Trump administration might assign to Chicago.

Generally, though, she said more agents are needed to investigate the “hits” the Chicago police receive on an ATF database that links bullet casings to guns used in crimes. The system is called the National Integrated Ballistic Information Network, or NIBIN.

“We are trying to beef up the manpower of the Chicago field office to address these 300 NIBIN hits every month,” Nunez said in a recent interview.

NIBIN can help the police determine if a gun that was used in a shooting was also used in other ones. Using the data, police can tie a shooting suspect to multiple crimes and see if a particular gang is causing most of the violence in a neighborhood.

In addition to NIBIN, ATF agents work with the police to investigate the ownership trail of weapons used in crimes.

Nunez said she plans to use the intelligence from NIBIN and gun-ownership traces to identify the shooters in Chicago’s gangs and pursue gun cases against them.

“If we stick to that, we can’t be accused of using biased techniques because we’re using scientific methods to say, ‘Here’s your trigger puller.’ ”

The ATF has been fighting allegations of bias in recent years.

In Chicago, dozens of African-Americans are seeking to have their charges dismissed, pointing to a study that found they were unfairly targeted in ATF stings between 2006 and 2013.

The U.S. attorney’s office here has denied any bias in those investigations, which involved fictional drug stash houses.

Chicago police have dealt with the proliferation of guns for years. These weapons, drugs and cash were seized in 2010. The firearm in the foreground is an AK-47 with a 75-round magazine. | Sun-Times file photo

In other cities such as Milwaukee, the ATF has come under fire for operating fake storefronts where informants directed potential criminals to buy guns from undercover ATF agents or even rob them.

An inspector general’s report found the storefront operations weren’t properly supervised. Critics have said those operations were biased, too.

Nunez said ATF’s policies on storefronts have been improved and they’re a “solid investigative tool.” But they’re not being used here, she said.

“We don’t have one and I don’t think it’s necessary in Chicago. With 300 hits a month [on NIBIN], we already have a lot to work on.”

Nunez said she’s working with the Chicago police and Illinois State Police to develop a new partnership to investigate firearms trafficking and identify gun offenders.

Nunez said she’s also met with officials in northwest Indiana to bolster joint investigations into guns crossing the border into Chicago.

She said she also plans to look at whether more gun cases can be prosecuted in federal court here.

Last month, the Chicago Sun-Times reported that federal gun prosecutions in Chicago were on the rise in 2016, but the number of cases continued to trail cities such as Detroit and St. Louis.

“Being new, I don’t know what the threshold is” for the U.S. attorney’s office to decide what gun cases to prosecute, Nunez said.

“Every U.S. attorney has a different threshold when it comes to prosecuting cases for firearms trafficking.”

Nunez said she plans to meet with Joel Levin, the acting U.S. attorney in Chicago, to discuss the issue.

Before he was replaced, U.S. Attorney Zachary Fardon said he had made gun crimes a top priority. | Santiago Covarrubias / Sun-Times

“I will find out why our numbers are low in terms of prosecuting cases here,” she said.

“I am going to look at the cases my agents are putting together, too, to make sure they’re meeting the requirements of the U.S. attorney’s office,” she said. “I will make sure my agents are working solid cases so that when they take it to the U.S. attorney’s office for prosecution, they should not be turned down.”

Of all the cases she’s worked, Nunez said she’s proudest of supervising the takedown of a murderous drug-dealing gang headquartered in a fortress called Torres de Sabana, a high-rise apartment complex in San Juan, Puerto Rico.

She said she encountered local police corruption during that probe.

The raid on the building was harrowing, Nunez said. She and her agents were briefly trapped inside — the doors were chained and locked by gang members — before a SWAT team rescued them.

Seventy members of the gang were charged in a 2010 indictment.

As she did in Puerto Rico, Nunez said she plans to target the “worst of the worst” of Chicago’s gangs.

Nunez said she investigated North Side gangs when she began her career here in 1999.

Today’s gangs are more difficult to investigate than in the past because they’re far smaller and don’t have corporate hierarchies anymore, Nunez said. Most gang factions in Chicago now only control a few blocks, their members are younger, on average, and they don’t answer to anyone, she said.

“It obviously makes our job more challenging now,” she said.

Despite the challenges, Nunez said her mission is to have an impact on violent crime here.

“I was in Seattle and I was watching CNN and I saw Eddie Johnson on TV saying this is not a police problem in Chicago, this is a societal problem. And I remember saying, ‘He’s right. I’m part of that society. I was part of that community. I want to go home and stop the bleeding.’ ”