The incident happened on a public dock along the Willamette River on Aug. 10, according to police.

PORTLAND, Ore. — Portland police detectives on Thursday arrested a security guard accused of using racial slurs toward a group of people, attacking a Hispanic woman with a baton and pepper-spraying two witnesses as he tried to get away.

The incident happened on a public dock along the Willamette River on Aug. 10, according to police.

Nathan Scates, 37, confronted a group of people on the dock near Tom McCall Waterfront Park.

Witnesses told police that Scates yelled at a Muslim family, called the women "whores," "terrorists" and said they needed to "go back to their country," according to court documents.

Scates then shifted his focus to a Hispanic man and woman, who witnessed the encounter, and began yelling racial slurs at them, court records said. The woman took out her phone to record Scates and he hit her with his collapsible baton, injuring her hand, police said.

Witnesses called 911 and the victims followed Scates as he walked away. Police said Scates used pepper spray on two people who were not the targets of his slurs.

Scates pleaded not guilty to second-degree assault, second-degree intimidation and second-degree unlawful use of a stun gun, tear gas or mace.