CUMMING — By the time Dennis Marx drove onto the Forsyth County Courthouse plaza June 6 and started a gun battle with sheriff’s deputies, he had already shot himself in the leg, according to information authorities released Tuesday.  

Sheriff’s office representatives included those details and others — including that some deputies had trained for just such an attack the day before — in a presentation at the morning meeting of the Lanier Forsyth Rotary Club.

The officials laid out a timeline of the events of June 6, as well as previous interactions the sheriff’s office had with Marx, who was scheduled to appear in court that morning to enter a guilty plea on drug and weapon charges.

The case against Marx dated back to August 2011. After making several undercover drug deals, authorities said they served a search warrant on him. During that raid, they seized several firearms from Marx, who was described as a devoted gun enthusiast.

Apparently upset at the loss of his guns and what he perceived as a personal attack, Marx began plotting the courthouse assault, according to authorities.

During the presentation, Sheriff’s Sgt. Richard Thompson shared some of the items that Marx brought with him to the courthouse. They included grenades designed to blow up as soon as the pin was pulled.

The grenades were attached to zip ties, and had 30-foot long pull strings, allowing them to be attached to someone and detonated remotely by pulling the string. 

Marx also had several homemade flash-bang grenades, improvised explosive devices and thousands of rounds of ammunition.  

According to sheriff’s officials, eight deputies fired a total of 62 shots at Marx on June 6, with four firing from inside the courthouse and the others from outside as they approached the rented Nissan Armada that Marx arrived in. 

They said Marx was struck 12 times, seven in the body and five in the head. Several other rounds also hit Marx, but were not counted because they were stopped by the double layer of body armor he was wearing, Thompson said.

That count also does not include the single accidental gunshot wound that Marx apparently inflicted on himself before heading out that day.

Thompson said it appeared that Marx accidentally fired his pistol as he was chambering a round, and that the .45 caliber bullet went in his thigh and came out below the knee.  

Officials speculate that the injury forced Marx to leave for the courthouse before he had finished loading his truck, since they found a backpack with even more booby-trapped grenades at his house. 

One shot fired by a deputy during the gun battle with Marx struck the County Administration Building, and another hit Cumming City Hall. No one was injured by either, according to Thompson.

Thompson said deputies had been training for just such a situation right before the shooting, with several officers completing an active shooter scenario just a day earlier.  

They had also recently received specialized training on how to deal with a courthouse attack, which included at least one scenario where someone drove a vehicle up to the front of the courthouse and attacked from inside of it, according to Thompson.

Ultimately, he said that a combination of luck, good training and “even a blessing from God” kept June 6 from being much worse.