Paul Caneiro, 51, was charged with one count of aggravated arson on Wednesday morning.
Two days after a couple and their two young children were found slain and their sprawling Colts Neck mansion set ablaze, the mystery of who killed the family continues, with no public signs of a possible motive.
Keith Caneiro, 50, was found shot to death in a yard on his property after firefighters rushed to a raging fire at his $1 million-plus Willow Brook Road home early on Tuesday afternoon, authorities said. His wife, Jennifer Caneiro, 45, and the couple's children, Jesse, 11, and Sophia, 8, were found killed inside the residence.
The mystery deepened Wednesday when authorities charged Keith's brother, Paul, with aggravated arson for setting his own Ocean Township home on fire early Tuesday morning. At the time he set the fire, Monmouth County Prosecutor Christopher Gramiccioni has charged, Caneiro's wife Susan and his two daughters were inside house.
Monmouth County Prosecutor Christopher Gramiccioni offered no possible motive and declined to identify any potential suspects in the horrific killings, which has stunned the wealthy suburb. It is still unclear if the fire at Paul Caneiro's home was related to the homicides some ten miles away.
Members of the Caneiro family could not be reached Wednesday. Neighbors could offer no explanation for the arson, painting a portrait of Paul Caneiro as friendly and low-key.
Who is Paul Caneiro?
Paul Caneiro doesn't have any previous criminal convictions, according to court records.
Neighbors described the family as nice and sociable. One neighbor also said Paul was a gun owner who sometimes visited the shooting range at the Old Bridge Rifle and Pistol Club. No one answered the phone at the club Wednesday morning.
Three neighbors outside the Caneiro home Wednesday said they were shocked by the charges filed against Paul.
"I mean, we're all shocked," said one neighbor, who did not want to be named. "This is unexpected."
Another neighbor, who also asked not be named, said Paul Caneiro and his wife, Susan, were at the home early Tuesday shortly after the predawn fire.
Paul appeared to be upset and left later in the morning, the neighbor said.
"He said it must've been a gas leak, he had tears in his eyes," another neighbor said. "Susan was devastated. He said, 'I'm in complete shock I can't believe this is happening to me.' They were here until about noon."
It's unclear where Paul Caneiro went after leaving his house.
What is known is that he was charged around 5 a.m. on Wednesday with the aggravated arson offense and then booked at the Monmouth County jail. A first court appearance for Caneiro has not yet been set.
In a statement to CNN, Paul Caneiro's attorney, Robert Honecker, said: "My client maintains his innocence on this charge and any other potential charge. His family fully support his defense of this charge. No evidence has been produced that suggests a reason why he would engage in such conduct. He fully expects to be vindicated when this case finally resolves."
What was the relationship between the two brothers?
A picture has begun to emerge of two brothers from Brooklyn who lived a more-than-comfortable life with their families near the Jersey Shore, where they managed several businesses together.
The office space occupied by Square One and EcoStar Pest Management. (Sophie Nieto-Munoz | NJ Advance Media for NJ.com)
Keith Caneiro is listed as the owner of both the technology firm, Square One, and EcoStar Pest Management in Asbury Park, working both businesses with his brother. Both firms are housed in office space above The Speakeatery restaurant, in a stately brick building updated with floor-to-ceiling windows overlooking Cookman Avenue.
Two small signs placed next to a door to the office space are the only indicators of the businesses' presence in the building.
Keith had operated Square One since 1987, according to his LinkedIn profile. Notably, however, the technology company has a limited online presence and no active website. Also unexplained is why both businesses seem to have few, if any, other employees other than the Caneiros.
A profile of the business in the Asbury Park Press said Paul Caneiro was his brother's first employee and eventually become the company's director of technical services.
Jared DeVincenzo, who works at Marketing Genome on the floor above the pest business and Square One, said Paul Caneiro was helpful when they suffered a break-in last year -- but he too offered little hint at a possible motive for the arson or if there was any trouble between the brothers.
"Paul was very nice with helping us with the recovery but other than that he's pretty quiet," DeVincenzo said Tuesday.
Paul Caneiro's house in Ocean Township. (Sophie Nieto-Munoz | NJ Advance Media for NJ.com)
What happens next?
In Colts Neck, hundreds gathered Wednesday night to mourn the family.
The same evening, the prosecutor's office confirmed the medical examiner office had positively identified the remains of the two children found in the house as those of Jesse and Sophia Caneiro.
A source told NJ Advance Media that federal officials are currently not involved in the investigation, although ATF's Newark Division indicated on social media that its arson investigators were assisting with the Willow Brook Road fire probe.
County and local investigators were still combing through the scene in Colts Neck as of Thursday morning.
While the medical examiner has conclusively pinpointed multiple gunshot wounds as the cause of Keith Caneiro's death, which has been ruled a homicide, investigators have yet to determine how Jennifer Caneiro and her children were killed.
At least one of the children had stab wounds, a law enforcement source told NJ Advance Media, but as of Wednesday night no weapon had been recovered from the scene.
If additional state charges are filed in the case, any defendants charged would not make an initial court appearance any earlier than Friday, as state courts are closed Thursday for the Thanksgiving holiday.
Vinessa Erminio, Ted Sherman, Noah Cohen and Thomas Moriarty contributed to this report.
Alex Napoliello may be reached at anapoliello@njadvancemedia.com. Follow him on Twitter @alexnapoNJ. Find NJ.com on Facebook.
Sophie Nieto-Munoz may be reached at snietomunoz@njadvancemedia.com. Follow her at @snietomunoz. Find NJ.com on Facebook.
Have a tip? Tell us. nj.com/tips