JACKSONVILLE, Fla. -

At a joint news conference by the Jacksonville Sheriff's Office, state attorney's office and Florida Department of Law Enforcement on Friday morning, Sheriff John Rutherford celebrated convictions of six members of the Grand Park gang in an investigation that began in 2007.

Rutherford said random acts of violence in the Northwest Jacksonville area escalated in 2007 and 2008, and residents believed they were done by people from other parts of town. He said they were reluctant and afraid to talk to police.

IMAGES: Booking photos of gang suspects

"A gang was operating in the area, and we were working these cases very hard," Rutherford said. "They were running a criminal enterprise at one time numbering 43 members and associates ranging in ages from 15 to 32."

Rutherford said investigators worked meticulously not just to keep piling on charges against the criminals, but to unravel the enterprise and in doing so completely dismantle the gang.

"These people are the poster children for the deadly 'don't snitch' attitude that can take hold of a neighborhood when criminal activity becomes a business and even the law-abiding become afraid to stand up and say, 'He did it; that's the person who shot my friend,' simply because they're too afraid to speak," Rutherford said.

By the end of 2010, detectives engaged the help of the Florida Department of Law Enforcement in its experience with the Racketeer Influenced and Corrupt Organizations Act. Rutherford said investigators worked closely with Assistant State Attorney Matt O'Keefe in building the cases.

"This team was determined to bring justice to those individuals who ran the neighborhood like terrorists who were out there running a third-world country," Rutherford said.

He said at that point the neighbors had had enough but were still reluctant to help police out of fear.

"But through the tenacious efforts of our detectives, slowly, victims, witnesses and even some of the suspects themselves began to tell the story of the Grand Park criminal enterprise," Rutherford said.

He said those indicted in the Grand Park RICO case in December 2011 all pleaded guilty to the multiple charges and have been sentenced or are awaiting sentencing.

The members of the gang were charged with 77 felonies and 65 misdemeanors. (See map.) Throughout the investigation, officers recovered 13 firearms and "a lot" of illegal narcotics, Rutherford said.

He said the leaders included Sedgewick Spicer and Johnny Hoover, who was shot and killed while his daughter and step-daughter were in a car with him. He said the hierarchy consisted of those who controlled the narcotics and made decisions as it related to the gang.

Others who pleaded guilty were Darryl Lundy, James Hall, Marcus Mitchell, Michael Merriwether and Warren Dixon.

"Attacking the enterprise is what will ultimately make the neighborhood a safer community," State Attorney Angela Corey said.

"This shows the need in a community: If you see something, say something," Rutherford said. "Reach out, work with the police. Do not let these kind of criminal enterprises take hold in your community."

Rutherford said the investigation is not over, but contrarily, there are numerous investigations that have been brought about as a result of this one.

"We have not seen a difference yet because it's still new," said Lloyd Washington, who heads up the neighborhood association. "This is the second time they have made such an arrest and they have come back. Hopefully it does."

City councilman Warren Jones said he's been working on trying to make changes on the street by re-zoning businesses where people loiter. He said the arrests are important, but he's not sure if they will do some good.

"What often happens is you take one person off the street, someone fills in that spot," Jones said. "It's somewhat like a revolving door, but I think it does send a positive message to the community."