A New Jersey police officer charged with shooting and killing a man on a Maryland highway in an alleged road rage incident has been released on $1 million bond.

Joseph Walker, 40, a sworn officer with the Hudson County Prosecutor's Office, was charged with second-degree murder and manslaughter after shooting 36-year-old Joseph Harvey, Jr. Saturday on an off-ramp on Interstate 97 near Millersville, according to Maryland State Police.

Police say the off-duty officer reportedly got into an argument with Harvey shortly after 8:30 p.m. while both men were driving on the interstate in Anne Arundel County, Maryland. Investigators say both men pulled over on the shoulder of the highway. Harvey got out of his car, along with his passenger, and starting walking towards Walker’s minivan.

Maryland State Police say Walker fired a .45 caliber Glock at Harvey and hit him. Harvey was pronounced dead at Baltimore Washington Medical Center.

Police say the officer’s wife and three children were in his car at the time of the shooting.

Police are investigating the shooting.

According to court documents, a witness told investigators that the confrontation started when Walker's minivan cut off Harvey's car on Saturday night. Harvey's passenger, Adam Pidel, told police that Walker pointed a gun at them as the vehicles swerved at each other.

Police say when the drivers got out, Walker announced he was a police officer. Pidel says he heard several shots as he ran for cover.