An off-duty police officer shot a man to death who allegedly showed up on his doorstep with a gun early Sunday.

Police say the 30-year-old officer opened the door to his home at about 5 a.m. to find a man standing on the doorstep demanding to see someone. When the visitor was told he had the wrong address, he allegedly pulled a gun on the off-duty officer.

The officer, also carrying a weapon, fired four shots. Two of those shots hit the man in the chest and ultimately proved to be fatal.

The man was taken to the University of Medicine and Dentistry of New Jersey and died shortly after the shooting. The officer was taken to the same hospital for a routine evaluation.

Three people accompanying the victim have been brought in for questioning.

AP wires contributed to this article.