A grand jury decided Friday that it did not have enough evidence to charge Clayton County Police Chief Greg Porter with racketeering, ending the legal case that alleged Porter was illegally paid more than $36,000 in federal grant money.

The grand jury’s decision came after more than eight hours of testimony from state investigators about whether Porter conspired to overbill Clayton County in a part-time job he once held monitoring participants in a court-ordered DUI program. Porter gave up the job once he was named chief in 2010.

But questions soon emerged about how the private business was run and whether Greg Porter, his brother Robert Porter, his wife Sabrina Porter and another woman, Katrina Hood, benefited from inflated bills. A criminal probe began in June when Clayton County District Attorney Tracy Graham Lawson asked the GBI to investigate. The proposed indictment, based on the GBI investigation, said, for example, that the business claimed it supervised probationers for 16 hours when the true time was four, for 15 hours when it was actually four, for 20 hours when it was only five.

After a day chock full of testimony from GBI agents, the grand jury deliberated for about an hour before deciding against indictment.

“Finally, the nightmare is over,” said defense attorney Lulu Ma, who represented Porter.

The police chief is no longer a target for prosecutors, said special prosecutor Chuck Spahos, who presented the case to the grand jury.

“Absent additional evidence we will not seek another indictment,” he said.

Porter left the Fayette County courthouse before the grand jury completed its work. As the evening wore on, Porter decided to keep his plans and attend the police department’s annual Christmas party.

He avoided becoming the second top Clayton law officer to face criminal charges. This fall, Clayton sheriff Victor Hill was acquitted of racketeering charges related to his use his county issued credit card.

At the same time Hill was fighting criminal charges, Porter was also fighting for his reputation and job. He was suspended without pay in July but he returned to the job in September.

After Friday’s verdict, prosecutors say the process worked as it should.

“The grand jury didn’t find probable cause to indict,” Fayette County District Attorney Scott Ballard. “They hashed it out thoroughly and I think they did what they thought was fair.”