Paul Caneiro's lawyer, Robert A. Honecker, did not immediately return a call seeking comment on the newest charges.
The Monmouth County Prosecutor's Office is slated to hold a press conference regarding the charges later Thursday morning.
The details of the heinous crime spree came just hours after Monmouth County prosecutors filed murder charges against Paul Caneiro in the November 20 eruption of violence in Colts Neck and Ocean Township, New Jersey.
All four members of Keith Caneiro's family were "victims of homicidal violence", the prosecutor said, adding there was no indication of suicide.
A financial dispute motivated a New Jersey man to kill his brother, sister-in-law and young niece and nephew and set their mansion ablaze before going to his home in a nearby community and torching the residence in an elaborate "ruse" to cover up his crimes, a prosecutor Thursday.
Keith Caneiro was shot numerous times on the lawn of his mansion in Colts Neck, an affluent horse country town that is home to rock star Bruce Springsteen, and where former "Daily Show" host Jon Stewart and his wife operate an animal sanctuary.
Prosecutors say financial motives led a technology executive in the USA state of New Jersey to kill his brother, the brother's wife and their young children before setting fire to their two homes.
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I do not have a smoking gun, but what I do know is that he was in charge of this agency that carried out the killing". The Saudi Public Prosecutor on Thursday added that the country had detained a total of 21 people over the killing.
Paul Caneiro is charged with murder in the deaths of Keith Caneiro, 50; Jennifer Caneiro, 45; and the couple's children, 8-year-old Sophia and 11-year-old Jesse, according to multiple news outlets, citing court records.
When police arrived at the scene, they found 50-year-old Keith Caneiro shot to death outside of the home and his wife and children stabbed to death inside of the home.
The woman's and the children's bodies were found severely burned inside the home, and authorities ruled out "a suicide angle", Gramiccioni said.
He was previously charged with second-degree aggravated arson after he allegedly set his own home on fire just hours before his brother and family were found dead at their home. He said the fire was started in two exterior locations at each end of the house. As a locally owned news organization, TAPinto through its advertisers is able to publish online, objective news 24/7 at no charge.
Paul Caneiro is listed as the vice president of Square One, and Keith Caneiro's LinkedIn profile describes him as the CEO and chief technology officer for Square One.
Keith Caneiro, he said, was "a super busy guy", but if he ever mentioned any work stress, it was "nothing relative to something like this". He will have a hearing at a Monmouth County court on Friday morning. "Have no reason to believe that's the case, think it was targeted".