COLTS NECK — A couple and their two children were shot, stabbed and left to burn by a relative in a rage motivated by financial greed, prosecutors said Thursday in an announcement that shed light on one of the most devastating murder mysteries in recent history.

The first-degree murder charges against Paul Caneiro, 51, were announced Thursday more than a week after the bodies of Caneiro's 51-year-old brother Keith, his 45-year-old sister-in-law Jennifer, 8-year-old Sophia and 11-year-old Jesse were found at the family's torched mansion.

Caneiro already had been facing aggravated arson charges for the Nov. 20 fire at his own Ocean Township home. But while authorities had said they were investigating the possibility that the fires at the two brothers' homes were related, Caneiro only was officially identified as a suspect on Thursday.

He remains in custody awaiting a hearing Friday in Superior Court. Prosecutors intend to ask a judge to keep Caneiro locked up pending trial. His attorney already has declared his client innocent of the charges that he torched his own home and any other charges that prosecutors would file in connection to the Colts Neck homicide.

Monmouth County Prosecutor Christopher Gramiccioni said Caneiro, who ran a computer security firm and a pest management company with his slain brother, was motivated financially but declined to elaborate citing court rules that bar prosecutors from unfairly tainting a criminal case through the media.

The timeline

Although the Colts Neck fire was reported hours after the Ocean Township fire, investigators believe Caneiro first killed his relatives and set the fire in Colts Neck before returning to his home about 5 a.m. Prosecutors say the fire at Caneiro's own house was both a "ruse" and in an effort to destroy evidence that he had taken from the Colts Neck home.

Jesse, Jennifer, Keith, Sophia Canerio. (Keith Caneiro via Facebook)

Gramiccioni said Caneiro repeatedly shot his brother outside his home. Inside, he shot and stabbed his sister-in-law and stabbed his niece and nephew, investigators say.

The Bureau of Alcohol, Tobacco, Firearms and Explosives says the Colts Neck fire was set in the basement. Gramiccioni said the fire smoldered for hours and later erupted into an inferno when somebody later went into the home: The opening of a door provided oxygen that fanned the flames.

The body of Keith Caneiro, with a gunshot wound to his head, was discovered by a landscaper, who alerted a neighbor. The fire was reported at 12:38 p.m. By the time responders found the victims inside, their bodies had been burned beyond recognition, officials said.

Investigators said they have possession of the knife and gun used in the slayings.

Gramiccioni said there is no evidence to indicate that the deaths and arsons are tied to organized crime.

Paul Caneiro's attorney, Robert A. Honecker Jr., says he heroically saved his wife and two adult daughters from the Ocean Township fire. Gramiccioni said investigators do not believe that he tried to kill his own wife and kids, but the gasoline-fueled arson put his family at risk, leading to the second-degree aggravated arson charges.

Honecker on Thursday said his client was innocent and that he had no reason to kill his family.

Community horrified

The violence committed days before Thanksgiving shocked a wealthy enclave not known for making headlines. Colts Neck is home to celebrities, executives and horse farms on multi-acre properties. But the shocking details of the family's death and the mysterious circumstances has drawn national attention.

Gramiccioni said the crime was so horrible that he would have sought to make this a capital case if New Jersey still allowed the death penalty.

Reporters questioned Gramiccioni why a business dealing with his brother would push a man to stab his own niece and nephew

On Thursday, the prosecutor addressed friends, relatives and neighbors of the victims.

"It’s not lost upon us how troubling and confusing this incident has been to you and how unusual these circumstances are as alleged. Our collective hearts in the law enforcement community go out out to you for the loss of Keith, Jennifer, Jesse and Sophia," he said.

"We won’t stop until we bring justice in the name of Keith Caneiro and his entire lovely family."

A self-made family man

Keith Caneiro, the middle of three brothers, appeared to be the picture of a self-made man. He took classes at Brooklyn College after high school and worked for free at a computer store to learn the ropes, according to a 2001 article on Square One in the Asbury Park Press, in which Carneiro identified himself as Keith Martin.

The company, then known as Jay-Martin Consulting after the brothers' middle names, had 26 employees at the time and installed computer systems for Citibank and interactive kiosks at the Statute of Liberty. Paul was his brother's first hire.

The company, and the brothers, moved from Brooklyn to the quieter New Jersey suburbs as the brothers married and had children. Obituaries describe Keith's children as 11-year-old Jesse, who liked World War I and II history, video games and sports, and 8-year-old Sophia, who loved ice skating, ninja classes and making cookies with her nanny. Funeral services for the family are planned Sunday.

In recent years, Keith Caneiro had earned a bachelor's from Columbia University's general studies program and, just this year, a master's degree from its School of Professional Studies.

Jennifer Caneiro was active at her children's school. She also enjoyed exercising, going to the beach and trips to a family home in Greece, her obituary said. She and Keith also took frequent trips to Atlantic City.

David Matthau contributed to this report.

Sergio Bichao is deputy digital editor at New Jersey 101.5. Send him news tips: Call 609-359-5348 or email sergio.bichao@townsquaremedia.com.