A new crime-fighting study identified 30 active street gangs in East Baton Rouge Parish with more than 500 members and found that a large percentage of area homicides during a two-year span have involved “known gang members” or gang-related violence.

Researchers working with the Baton Rouge Area Violence Elimination project reported that 43 percent of the 199 murders occurring between September 2010 and October 2012 were confirmed to be “gang-member involved murders.”

An additional 12 percent of the killings were found to “likely” be “gang-member involved murders,” a classification that includes homicides in which the victim or suspect is a known gang member.

That classification also includes cases where specific gang affiliation was undetermined but the circumstances of the murder fit the criteria for gang-related violence.

“An underlying assumption is that while violent acts are often perpetrated by individuals, they are rooted in a group dynamic,” according to the report, prepared by the University of Cincinnati Institute of Crime Science. “Once these chronic violent offenders are identified, disruption of gang violence occurs in multiple ways.”

Local law enforcement officials assisting the researchers were asked to provide information on all types of violent street groups in the area, regardless of the gang’s organization, size or sophistication, the report noted.

East Baton Rouge Parish District Attorney Hillar Moore III, who previously declined to refer to such groups as “gangs,” said he was surprised by the report’s findings. But he said the types of gangs found in Baton Rouge are no different from street gangs “that every community has.”

“I think we’re on par with other cities our size,” Moore said in an interview, “and I believe that we’re fortunate that we don’t have the really traditional gangs and issues that other cities have.”

The report was presented Monday at a quarterly meeting of BRAVE officials, who are making final preparations for the project’s first “call-in” session scheduled to take place within the next few weeks. About 40 gang members will be invited to the sessions, where they will be offered an opportunity to change their lifestyle and warned of the consequences of committing violent crimes.

Many gang members are under a form of legal supervision, the report says, so they can be required to attend the notification sessions. Gang members attending call-in sessions “should be systematically tracked to identify who has received the focused deterrence message and how the message is disseminated within the gangs across the city,” the report states.

“If you or a member of your group commit one of these crimes, all 700 (police) officers are coming after you and your group,” Moore said at Monday’s meeting.

Baton Rouge’s street gangs, which range in size from four to 60 members, include between 580 and 647 individuals altogether, the report estimated. Of the 30 gangs parishwide, 26 operate within the city limits.

Twelve gangs were classified as “high-violence gangs,” while eight were labeled “medium-violence gangs.” Another 10 were called “low-violence gangs,” the report found.

The BRAVE program has identified 396 gang members by name or nickname and created a citywide gang-member database that law enforcement can use to track activity, according to the report. Police and sheriff’s officials gathered crime reports and used information in them to map the social patterns of the gang members.

“With every kid that gets arrested that’s related to a gang, all the antennas go up,” Moore said.

One gang, the Baby Guerillas, has 41 members and has drawn particular attention from law enforcement because of its clashes with a rival gang, BRAVE Director Herbert “Tweety” Anny said. The report found the Baby Guerillas has two “active feuds,” three alliances and one “volatile relationship” with other local gangs.

“In other words, they’re the groups that are most likely to either shoot somebody or to get shot themselves,” Anny said.

Fueled by a $1.5 million federal grant, the BRAVE project has been largely focused on the 70805 ZIP code, a troubled area that the report notes has a violent crime rate 25 times higher than the national average.

But the new report also makes clear that effort should be extended to other areas of concern, such as the 70802 ZIP code. The report notes that 70802 had just as many confirmed or likely “gang-member involved murders” — 27 — as the 70805 ZIP code over the two-year period considered in the study.

“The data reported suggests that although this area (70805) has been extremely problematic, other areas in Baton Rouge also have significant problems with gang-related violence,” the report concluded.

The report also notes that the artificial boundary of the 70805 ZIP code cuts through identified gang territories.

“This provides another indication that the original scope of Project BRAVE should be widened to include the entire Baton Rouge area,” the report adds.

While BRAVE officials have acknowledged the work that lies ahead, Moore told his colleagues Monday that he was thrilled to see a sharp drop in the number of homicides in February and March after a violent January that saw several slayings. But he said it was too soon to attribute the lull to the BRAVE effort alone.

Moore said he saw an unusual yet encouraging sign at the scene of a fatal shooting in February.

“There were 14 homicide detectives there because they had absolutely no other murders to work,” Moore said, “which is a really good feeling.”