CHICAGO — The idea seemed simple though bold: Call reputed gang leaders to a meeting with top police and federal prosecutors and deliver an ultimatum to end killings in the nation’s third-largest city.

But Chicago police Superintendent Jody Weis is facing mounting criticism for holding a so-called “gang summit” last month, even though several police departments across the country have relied on that approach for decades to help reduce crime.

Among the chief complaints: that Weis himself was at the meeting, that the department should instead be adding more officers on the streets and that gangs won’t take the message seriously.

“What are we doing negotiating or having a sit-down with urban terrorists who are killing with guns and drugs on the streets?” Chicago Alderman Bob Fioretti said. “Gangs are not to be coddled.”

The issue resonates deeply in Chicago, where the number of brazen shootings has escalated this year, even though the overall homicide rate is down. Earlier this year, two state lawmakers asked to send in the National Guard to patrol streets. On Wednesday, two cops were shot and injured while serving a warrant.

The Chicago Gang Violence Reduction Initiative launched at an unpublicized Aug. 17 meeting, when Weis met with parolees and reputed gang members from Chicago’s west side. The meeting, which was also attended by family members of victims, was first reported by the Chicago Sun-Times.

Some reputed members of gangs like the Four Corner Hustlers and the Traveling Vice Lords said they were surprised to see Weis there after being told by their parole officers to show up. Many were visibly angry and some left during the meeting.

But Weis has defended the initiative with the support of Mayor Richard M. Daley and U.S. Attorney Patrick Fitzgerald, who likened the tactic to his office holding parolee forums to warn people leaving prison that they’ll be watched.

Weis said the message was simple: “If you should resort to violence, we’ll sharpen our focus on you and really really make your lives uncomfortable. You have the ability to influence people within your sphere. You guys are in the position to stop the killing.”

Weis said prosecutors at the meeting threatened attendees that they could be charged under the Racketeering Influenced and Corrupt Organizations Act if killings were traced back to gangs with members attending the meeting. The federal law, commonly known as RICO, provides stiffer penalties for acts performed as part of a criminal organization such as the Mafia.

Experts say the tactic of meeting with gang leaders — whether formally with top administrators or at the neighborhood level — is just part of good police work.

“It’s become almost standard practice in police departments around the country,” said David Kennedy, director of the Center for Crime Prevention and Control at John Jay College of Criminal Justice in New York. “It’s simply saying to people that violence is going to get special attention from law enforcement and that a whole lot of violence, especially in places like Chicago, is driven by gangs.”

At least 50 jurisdictions nationwide use the approach. In Cincinnati, Chief Tom Streicher Jr. attends similar meetings, and the Los Angeles Police Department has started using the approach.

Among the pioneers was the Boston Police Department. In the early 1990s when the city’s murder rate hovered around 150 a year, the department launched Operation Ceasefire, which continues today.

Parolees and other alleged criminals attend meetings with prosecutors where they’re warned of consequences and given jobs information. Police say it has helped cut Boston’s homicide rate. Last year the department reported 49.

“We give them a conversation about the fact that we know who they are, what they’re up to and they have two options,” said Boston police spokeswoman Elaine Driscoll. “Take advantage of the resources or end up in jail.”

Still, criticism in Chicago has continued.

“I don’t think that’s the way to go,” Illinois Gov. Pat Quinn said. He suggested going after guns on the streets.

Fioretti, who is mulling a run at Chicago mayor, said Weis shouldn’t have been there with reputed gangsters.

“He brought them to a table and made them equal,” Fioretti said.

Chicago Alderman Joe Moore has called it “a desperation tactic,” while others have suggested younger and active gang members may not listen to the word of parolees.

Some of the scrutiny could simply be because it was Weis’ idea.

Since he took over in 2008, the department has been wary of Weis, a career FBI agent who continues to be seen as an outsider by many rank and file officers.

Weis noted the program hasn’t incurred big costs and that if it doesn’t work, the department will drop it. He said he thinks his presence at the meeting made it more meaningful and that attendees were chosen because of their influence.

Overall, Chicago’s homicide rate has mirrored national trends and dropped significantly since the 1990s. It fell from a high of 943 in 1992 to 460 last year and has held steady in recent years.

But if residents and police need evidence that the city remains a dangerous place for officers — four officers were killed in the line of duty this year — they found it Wednesday morning. Two plainclothes officers were shot and wounded while serving a warrant on the city’s South Side.

Weis said the next step is to determine if recent crimes can be traced to gangs at the meting.

“I don’t view it as the panacea to stop all crimes,” he said. “It certainly seemed like a worthwhile effort, even to try.”