APOLLO BEACH — Along Silver Falls Drive, lawns are lush, sidewalks are spotless and neighbors clean up after their dogs.

Residents there say they lived in relative harmony — until one homeowner inside the gated, adults-only community began disrupting the peace.

John Gallik, who lived at 119 Silver Falls Drive, turned his lawn into a "perpetual garage sale," records show. Neighbors say he was aggressive, yelled profanities and threatened them. And he liked to put up handmade signs, on his lawn and around his neck, that detailed his ire with his Southshore Falls subdivision.

On Thursday, his often erratic behavior spawned violence.

David Cockerham was walking his dog when it knocked over a sign on Gallik's lawn that partially blocked the sidewalk. As Cockerham tried to move the sign, Gallik stormed outside, said Hillsborough County Sheriff's Office spokesman Larry McKinnon.

Cockerham took a few steps back. But Gallik thrust a butterfly knife toward Cockerham, threatened to cut his throat and charged toward him, deputies said.

Fearing for his life, Cockerham pulled a .38-caliber revolver from his pocket, deputies said. He fired once at Gallik's chest.

Gallik, 52, died on his lawn.

On Friday, word of the men's confrontation and Gallik's death was the talk of the neighborhood.

Some neighbors expressed surprise and dismay. For others, Gallik's death brought relief.

"They're glad it's over," said Jerry Kelley, who lived five houses away from Gallik and witnessed Thursday night's shooting. "Nobody wanted this to happen. They just wanted him to get out. He was trashing the whole neighborhood."

Cockerham, 67, called 911 after shooting Gallik. He was taken into custody, but later released. Once detectives complete their investigation, it will be handed over to the State Attorney's Office for a final ruling, McKinnon said.

Cockerham, who does not have a criminal history in Florida, could not be reached for comment Friday.

Rod Feger lives next door to Cockerham. He said Cockerham is a quiet man who recently retired from teaching. "Not boisterous or anything," he said.

The fact that Cockerham carried a gun while walking his dog is "irrelevant" to the case, McKinnon said.

"This is Florida, where a lot of people carry concealed weapons," he said. "There's no neighborhood that's immune to violence."

Gallik was not always the neighborhood eccentric. He and his wife moved into the Southshore Falls subdivision in 2007.

But more than a year ago, his wife moved out, Kelley said.

"He's been downhill ever since."

Gallik began to throw trash on his driveway and toss beer cans onto his roof. A barrel, card table, motorcycles and a refrigerator all littered his front lawn at some point, neighbors said.

Then he stopped paying his utility bills. Last month, the county placed a lien on the home for the lack of payments.

Nine days before Gallik's death, Southshore Falls filed a request for a court injunction, which outlined some of Gallik's behaviors.

According to the court filing, Gallik wore a sign around his neck that read, "Death to Southshore Falls." He bathed outside, ran a generator, hung wet clothes in the front yard, solicited donations of food from neighbors and threatened a neighbor to get electricity for his computer, records show.

The filing also paints a tense picture of Gallik's relationship with his neighbors.

He threatened them, posted "foul and offensive" signs, allowed his dog to defecate on the street and verbally abused neighbors to the point that they called the sheriff's office.

In the filing, the association sought to make Gallik comply with HOA rules and pay fees to bring his home up to code.

Neighbors, such as Nancy Fox, avoided the house.

"I just felt that he was not stable," Fox said. "He seemed kind of territorial."

On June 4, deputies received a report about a "mentally ill person" at Gallik's address. The following day someone reported a suicide attempt at the house, records show.

Gallik had no criminal history in Florida, records show, but he served five years of probation in New Jersey after pleading guilty in a 1996 aggravated assault case.

One of his Southshore Falls neighbors recently reached out to him, helping him activate his food stamp card and driving him to a social services agency to seek financial help from the county.

But it wasn't enough.

"It's a shame," said Feger, a neighbor, "that he couldn't have been helped."

Times staff writer Robbyn Mitchell and researcher John Martin contributed to this report. Laura C. Morel can be reached at lmorel@tampabay.com.