The Colts Neck man accused of killing his brother, sister-in-law and their two small children once threatened a co-worker with a screwdriver and warned he could “have a fatal accident,” the ex-colleague claims

IT consultant Mark Bostrom says that all it took was a newscaster to utter the name Paul Caneiro — who’s been charged with shooting his brother, shooting and stabbing his sister-in-law and stabbing both children before setting fire to their house in November — for his own terrifying encounter to come rushing back.

“I knew that name,” Bostrom wrote on his local news blog Friday, as he worked on a project with Caneiro 27 years ago. “Then I saw the mug shot. I recognized the face.”

The two crossed paths in 1991 after Citibank hired the accused murderer’s firm, which Caneiro ran with the help of his brother Keith, to install a computer system in the bank’s Chicago office building.

But the project was plagued by problems, including several network outages, according to Bostrom.

Late one night, Bostrom was working with Paul Caneiro when he cracked a joke that could have cost him his life, he says.

“I walked over to ask him if the ‘notwork’ was going to be up soon — teasing him since the network was not working,” Bostrom wrote.

“He was examining some blueprints and became incensed with my comment. He picked up a screwdriver off of a table and said, ‘you know you could have a fatal accident back here’ while slowly moving the screwdriver up and down.”

The thinly veiled threat shook Bostrom, who reported the incident to local cops.

“The message was clear: He thought he could kill me and make it look like an accident,” he wrote.

Nothing ever came of his complaint, but Bostrom, 60, says his dealings with Caneiro became “a little strained.”

Caneiro, 51, has pleaded not guilty to killing his brother, sister-in-law and his 8-year-old niece and 11-year-old nephew.

Authorities say he also set fire to his brother’s home, as well as his own house, to make it seem like someone was targeting his family.