The four have been charged with murder, felony murder, carjacking, conspiracy, possession of a weapon and possession of a weapon for unlawful purpose. They are being held on $2 million bail each.
The suspects have been identified as 29-year-old Hanif Thompson, of Irvington; 31-year-old Karif Ford, of Newark; 32-year-old Basim Henry, of Newark; and 33-year-old Kevin Roberts, of Newark.
Ford and Roberts were arrested in Newark, Thompson was arrested in Irvington, and Henry was arrested early Saturday morning at a hotel in Pennsylvania.
Dustin Friedland, a 30-year old lawyer from Hoboken, was shot in the head Sunday night inside the mall's parking garage.
Authorities found his SUV the next day about ten miles away in Newark.
Police say Friedland had just opened the passenger door for his wife and was about to get in the driver's side when he was approached by two men and shot. Witnesses described hearing three gunshots.
He was rushed to Morristown Medical Center, where he later died. The victim's wife was uninjured but was also taken to the hospital.
Authorities say the four suspects came to the scene together in a Chevrolet Suburban, and two of them fled driving the victims' vehicle. It has not been revealed which of the suspects fired the shots.
According to Acting Essex County Prosecutor Carolyn Murray, the attack was motivated by a desire to steal the particular vehicle, a 2012 silver Range Rover.
She attributed the arrests to "good old-fashioned police work" and leads from the public.
"The sheer senselessness of this case outraged people from Millburn to Newark," Murray said, referring to towns in Essex County, whose borders encompass crime-plagued Newark to the east as well as Millburn, Short Hills and other affluent suburbs to the west.
Friedland had a law degree from Syracuse University and was project manager at his family's heating and air conditioning and heating company in Neptune.
The attack was the latest in a recent wave of carjackings in Essex County.
More than $40,000 was offered for information leading to the arrest of the killers.
"We are very grateful to the Essex County Police and all of the local authorities for pursuing this so vigorously," the victim's wife, Jamie Schare Friedland. said in a statement issued Saturday afternoon.
The Associated Press contributed to this report.
CLICK HERE TO SEE PHOTOS OF THE RECOVERED VEHICLE AND THE CARJACKING SCENE