Harrison Police stopped a vehicle occupied by two men for moving violations near Passaic and Harrison avenues Sunday at around 5 pm.
Police said as the officer interviewed the driver, he smelled marijuana and asked the two men to exit the vehicle while another officer monitored them near his patrol unit.
During a search of the vehicle, the officer found a loaded Taurus .45 caliber handgun and a police scanner.
The officer immediately ordered both men to the ground and informed them they were under arrest.
Authorities said the driver complied, but the passenger immediately sprinted from the scene.
A brief foot chase ensued but officers were unsuccessful in capturing the suspect. Newark Police were informed of the details and the direction of flight which was over the Bridge Street bridge into Newark.
Newark Police were also unable to apprehend the suspect.
The incident remains under investigation.