More than a week after a tense standoff on Interstate 95, officials released more information about how the incident with a group called Rise of the Moors was resolved peacefully.

SWAT teams used a Long Range Acoustic Device (LRAD) to disable the defendants to end the July 3 Wakefield standoff, WCVB reports.

On July 3, State Police encountered nearly a dozen men on I-95 who were heavily armed and wearing body armor. The self-proclaimed militia group was traveling from Rhode Island to Maine for some type of training. None of the men have any licenses to carry weapons, investigators said.

The nine-hour standoff ended peacefully, with all the men taken into custody.

On Monday, Wakefield’s police chief told the town council how NEMLEC, the North Shore’s regional SWAT team, deployed a “sonic cannon” to help capture the suspects. “NEMLEC deployed what’s called an LRAD. An LRAD is a high-pitched audible alarm that disables somebody temporarily,” said Chief Steven Skory. “We deployed that and were able to successfully take the remaining people into custody.”