That was Sept. 28, 2000, at Hickory Tree Elementary School when a school librarian reprimanded him.
When the school's social-skills coordinator intervened, Penney claimed that "I was just going to hit her with the gun, because Dad put the bullets away and has a safety lock on his guns." The incident was resolved by assigning the youngster to complete a stop-and-think drawing.
As years passed, Penney collected hundreds of toy guns until he turned 18 last year and began buying AK-47 assault rifles. His anger grew with this deadly collection as he practiced Satanism and brooded over rejection, greed, racism and hypocrisy, investigative records say.
Then last fall, police say, the teen opened fire on St. Cloud homes, residents and police in what first appeared to be rage over a car accident.
The shooting on Alabama Avenue had been planned for days, weeks or months to force police to kill him, recently released records show. But the plan failed. Penney shot himself in the head shortly before 2 a.m. Nov. 21 but did not die.
Except for the zero death toll, the shooting was reminiscent of America's worst massacres by heavily armed lone gunmen with histories of mental illness or grievances against society.
Penney matched or outdid the others by dressing in military gear and carrying two AK-47s with 150 rounds of ammunition in five magazines as he methodically fired at homes and cars lining the street.
When police approached after he shot himself, they found an AK-47 strapped across his back and another by his side. Despite a gaping face wound and mangled tongue, Penney told them why he had ambushed two police officers.
"Because I wanted to die," he said, records state.
Now held in the Osceola County Jail, Penney faces trial on charges of attempted murder of police officers and numerous shooting-related crimes.
The case against him relies, in part, on a suicide note and social rant titled, "Why I left."
It was found in his family's East Lake Tohopekaliga home along with survival manuals, works on demonology and a detailed log of more than a dozen assault weapons he had intended to buy, records show. No idle dreamer, the funds were supposed to come from a bank account holding more than $60,000 in child-support payments, records show.
"I apologize to law enforcement … they could never have known my plan was suicide, for all they knew I could have been trying to kill others," he wrote. "I would never harm a person, despite what some think. I love people and could never be a murderer."
Contrary to his claim of not wanting to kill anyone, Penney is charged with firing at the head of Officer Spencer Endsley and shooting Officer Clinton Wise in the foot during the ambush. About a dozen bullets hit their patrol car, including three that tore through Endsley's headrest and sprayed him with glass fragments, records show.
Besides firing at police, Penney is accused of riddling the home of a young St. Cloud man who wrecked the teen's car two months earlier without paying for the damage. Altogether, Penney fired 95 shots, according to the Florida Department of Law Enforcement.
After the shooting, police found signs of extensive planning.
On one of two laptops that Penney used to write his death note, Detective Curtis Wesler discovered Penney used Google to research "suicide by cop." The aspiring writer filled his five-page suicide rationalization with self-loathing.