Robert W. Nicol is being held in the Ada County Jail on a felony aggravated assault charge after police say he hid under a blanket in the back seat of a Boise woman’s car and then threatened her and a man in the front seat with a gun early Saturday morning.

Boise police officials declined to define the relationship between the 23-year-old Nicol and the two victims but did say they are well known to each other and the fight appears to be part of a ongoing dispute.

Police also say other charges are possible against Nicol, who got into a fight with the other man both inside and outside of the car early Saturday morning.

This is what police say happened.

The man and woman were driving to an undisclosed location around 3 a.m. Saturday when they told police Nicol emerged from the back seat, where he had been hiding under a blanket, and attacked the other man in the front seat of the car.

That’s when police say the woman stopped the car near the intersection of Overland Road and Shoshone Street. Witnesses told police all three people got out of the car and the fight between the men continued. Police reports are not clear about when Nicol threatened the couple with a gun — if he did it in the car or out — or where he got the gun.

Police were called to the fight by a third party who saw what was happening and called 911.

Police arrived and arrested Nicol a short time later. The other man was not charged in connection with the fight.

Nicol will make his initial court appearance Monday afternoon.

The charge of aggravated assault is punishable by up to five years in prison.