ST. THOMAS — Residents of Anna’s Retreat were alarmed by a volley of gunfire that went on for at least 30 minutes Wednesday night — a test of the ShotSpotter gunfire detection system that was conducted without prior warning from V.I. Police.

ShotSpotter is a private acoustic technology system employed by police departments in more than 100 cities across the United States, the U.S. Virgin Islands, Puerto Rico, South Africa, and the Bahamas, that uses sensors to alert law enforcement to gunfire, and can help reduce response times and get gunshot victims emergency treatment.

- Contact Suzanne Carlson at 340-714-9122 or email scarlson@dailynews.vi.