The man fatally shot by a New Orleans police officer Saturday after taking his pickup on a rampage through the Lower 9th Ward had a lengthy history of mental illness and violent mood swings that kept his community on edge for years, according to interviews with a half-dozen neighbors.

Christopher Olmstead, 60, clashed repeatedly with his wife and became enraged at times by the sounds of young children playing in his vicinity, neighbors said.

A veteran who seemed to be “at war with himself,” he once fired a crossbow into a yard two doors down during one of his fits, said one neighbor, Sherman Johnson.

On another occasion, two neighbors said, Olmstead pointed a gun at youngsters playing basketball next door to his Flood Street home.

“The dude was wild,” Johnson said outside his home Monday. He recalled Olmstead’s personality as “up and down,” saying he never knew which “Mr. Chris” he would encounter on a given day.

“One day he’d be singing, and the next thing you know, he’d be cussing and throwing chairs,” Johnson added. “He would have some real heavy rages. You could hear him throwing stuff around the house, screaming and hollering to the top of his lungs.”

Despite this volatility, neighbors said they watched in disbelief early Saturday as Olmstead flew into a fatal hysteria.

After yet another argument with his wife, he apparently set out looking for her, backing through a wooden fence behind his driveway and plowing his pickup into a parked car and a home across the street — the residence in which his bleeding wife that morning had sought refuge.

Unsatisfied, he accelerated through the yard of neighbor Danny Santiago, taking out a doghouse and arbor before slamming into another vehicle parked near the intersection of Caffin Avenue and Chartres Street. In his wake was a strewn trail of car parts and damaged property.

Santiago said the smell of burnt rubber filled the air.

“There was always an episode with Chris because he was a mental patient,” Santiago said, adding that his neighbor had been committed for psychiatric treatment at least twice. “The police had come there frequently.”

Indeed, officers were called to Olmstead’s home on at least four prior occasions this year, including an incident Thursday that New Orleans Police Department spokesman Tyler Gamble described as a “mental disturbance.” The next call for help — a report of domestic battery — came about 9:09 a.m. Saturday, Gamble said.

Neighbors said they had heard screams from Olmstead’s home as early as 3 a.m. At some point, the man’s wife fled the residence and, as she had done previously, took shelter at Santiago’s home across Chartres Street. Santiago said he believes Olmstead figured out where she had gone because one of their dogs followed her and apparently was lingering outside Santiago’s home.

Detective Timothy Bender, a veteran homicide investigator, happened to be in the Holy Cross neighborhood investigating an unrelated case when he was flagged down by someone who spotted Olmstead driving erratically. The detective was driving an unmarked police vehicle but was wearing an NOPD uniform.

Bender appears to have arrived at the scene shortly after Olmstead crashed into the second vehicle. The detective repeatedly ordered Olmstead to get out of his pickup, witnesses said. When he finally did, Olmstead charged at the detective, according to Sarah Lastie, a neighbor who witnessed the shooting and said it was like “looking at a movie.”

“He came raging after the officer,” Lastie said. “The officer did not want to shoot him. He tried to get him to give up, but he wouldn’t do it. He didn’t have any choice but to shoot him.”

Police said Bender opened fire in self-defense. Olmstead was struck several times and had wounds in the front of his neck, chest and abdomen, said Dr. Jeffrey Rouse, the Orleans Parish coroner.

Bender, who was reassigned to desk duty pending an investigation by the department’s Public Integrity Bureau, appeared to be “very upset” over the shooting, Lastie said.

Olmstead was not carrying a firearm, but police said they are still investigating whether he may have been armed with some other type of weapon. A source familiar with the case said investigators believe he may have been wielding a wooden stick, which was found near his body.

“From what we have initially, it’s clear that (Olmstead) was the aggressor,” Gamble said.

Homicide detectives are not required to wear body-worn cameras, so investigators won’t have footage of the incident to review.

While working for the Louisiana State Police in 1999, Bender was accused of grabbing a motorist by the throat and making “inappropriate remarks.” The motorist, Bobby Youngblood, had been pulled over in Bogalusa and later filed a lawsuit against Bender and several other law enforcement officials, claiming he was beaten mercilessly.

The complaint was deemed to be “sustained,” and Bender, now a well-known NOPD detective who has been featured in “The First 48” reality TV show, was suspended for 45 days. The Louisiana State Police Commission overturned the punishment on appeal, finding in 2002 that a “parade of eyewitnesses” had failed to establish the facts alleged in Bender’s letter of suspension.

In the Saturday shooting, neighbors said they were convinced Bender had pulled the trigger as a last resort. Still, Susan Hutson, New Orleans’ independent police monitor, said she believes the department should “re-evaluate how officers approach and interact with members of the public.”

“Officers must be taught better tactics on how to approach situations of grave risk,” Hutson said in a statement, commending the department for sending two officers recently “to be trained in how to teach de-escalation tactics.”

Sifting through the aftermath Monday, Santiago said the rampage had left his Chartres Street home uninhabitable and had totaled his wife’s car. He said he’s not sure whether his insurance will cover the damage, which he put at roughly $70,000.

The entire neighborhood remains traumatized, he said, in part because the incident happened just two days after a mentally ill gunman opened fire in a movie theater in Lafayette, killing two people before taking his own life. Santiago drew troubling parallels between the two incidents.

“It was almost the same circumstances,” he said, in that Olmstead suffered for years from mental health issues but apparently did not receive the treatment he needed. “But for the grace of God, he apparently didn’t have a firearm.”

Follow Jim Mustian on Twitter, @JimMustian.