Police said John Spears was standing Friday afternoon outside the Kenner maritime skills development center where he worked when he told a fellow employee who was leaving early, “You’re going to miss all the fun. I’m about to go back inside and shoot everybody.”

That person considered Spears to be mild-mannered and free of conflicts with any of his colleagues — so the co-worker believed it was a joke and didn’t tell anyone about the alarming remark, Kenner Police Lt. Brian McGregor said Monday.

Yet it would soon become clear Spears did intend to commit violence, police allege. About 30 minutes after his remark to the co-worker, McGregor said, Spears walked inside Houston Marine with a .40-caliber handgun and fatally shot facility manager Anthony Tardo once near the heart.

Spears then stepped back outside and calmly waited for police officers responding to 911 calls to place him under arrest and jail him on a count of second-degree murder.

Three days after the incident, there still didn’t seem to be any answers to questions about what might have driven Spears, 51, to kill Tardo, 49, a Mandeville resident and longtime Houston Marine employee who is survived by a wife and triplets.

However, court records show Spears had experienced serious workplace problems at a previous job, even as police and company officials insisted there was no reason to think he was having a dispute with anyone at Houston Marine, located in the 2500 block of Williams Boulevard.

Spears had spent about two years working offshore on an oilfield vessel belonging to the firm Oceaneering International when he told his supervisors he wanted to pursue the rank of captain in late 2001.

But Spears — who had been serving on vessels for about a dozen years at the time and was looking for an increase in salary — said his superiors’ attitudes toward him changed immediately, and he began receiving negative performance evaluations after previously getting consistently positive ones.

He also filed a complaint saying a male engineer began to sexually harass him, stroking his leg or otherwise fondling him.

Spears said it all led to his firing in April 2002. The Marrero resident later got another job but nonetheless sued for damages in 24th Judicial District Court in Gretna, alleging that he had been the victim of racial discrimination as the only African-American on his vessel as well as the highest-ranking black employee in Oceaneering’s fleet.

Oceaneering denied Spears’ claims, asserting that he was fired for legitimate business reasons. The company said his unfavorable performance evaluations and termination occurred because he disliked doing required paperwork, lacked initiative and delivered poor work.

The company also said that, while Spears’ sexual harassment complaints were being investigated, multiple employees reported that he would expose his buttocks to colleagues and ask whether they wore their wives’ panties as he did.

When confronted, Spears claimed he didn’t remember whether he had done any of that, according to the company, which found his sexual harassment complaints to be unfounded.

However, Oceaneering said Spears did admit to regularly joking in a profane manner because that was done “in general when there’s a group of men there” on a vessel. The company said it fired Spears only because there were no less demanding positions to which he could be assigned when his work began suffering.

Each side agreed to settle the case before it went to trial after Oceaneering successfully moved for the dismissal of the harassment claims.

The company said Spears admitted there was nothing it could do to prevent him from obtaining one of the captain’s licenses issued by the U.S. Coast Guard if he chose to seek it.

Attorneys involved with the case would not discuss the value of the settlement Monday.

Spears’ and Tardo’s families both declined to comment.

If Spears — an instructor at Houston Marine for the past year — was harboring some frustrations there, it wasn’t obvious to those around him.

“We can’t find any indication that makes sense for why this happened,” Bryan LeCompte, the CEO of Houston Marine corporate owner Falck Safety Services, said Monday. “It seemed status quo, like an employee who was doing his job.”

Likewise, several of Spears’ neighbors in Marrero expressed disbelief that he could have committed a murder.

Betty Hunter, 77, who lives across the street from Spears, wiped back tears at the thought. She said she helped raise Spears from when he was little and knew him as a devoted, churchgoing father of two adopted children.

“I’d like to know what happened (to cause this) because it had to be something,” Hunter said. “It seemed as though he liked the job.”

Spears remained in jail Monday in lieu of $750,000 bail.

If convicted of second-degree murder, he faces a mandatory sentence of life in prison.