Explosions and gunshots in Atlantic City on Friday were a sign of safety — not danger.

In the afternoon, a New Jersey Emergency Preparedness Association demonstration helped first responders know what makes an explosive mix and how it looks and sounds. Later, live gunshots were used to test the city’s new system that will alert police when a gun is fired.

Atlantic City’s Bomb Squad, State Police and the FBI helped set up the live demonstration at Bader Field that included showing the results of mixing easily — and legally — obtainable ingredients for explosive effects.

“The chances (first responders are) going to see these things before we do are pretty good,” said Lt. Jerry Barnhart, head of Atlantic City’s Bomb Squad, which helped set up the demonstration along with the FBI and State Police.

When people are hurt making explosives, they are going to call for an ambulance, not the police, he noted. So, if an emergency medical technician sees a specific mixture together, they may be alerted to the possibility of an explosive.

“It’s good for people to see this kind of stuff,” said association President Michael Bailey, a former Ventnor police officer and firefighter. “We’re fortunate to have a live demonstration here.”

He estimated about 50 departments were represented at the demonstration.

FBI Special Agent Bomb Technician Chris White showed how certain ingredients — which officials asked not be published — could be mixed to get explosions similar to that of the real thing. Then, the group got to see the differing — and sometimes very loud — results.

“This really underscores the dangers of (these chemicals) as far as how to identify them and when to call the bomb squad,” White told the group.

Before the demonstration, Atlantic City police put out a warning to residents that the explosions might be heard. Some were loud enough to be reported in Brigantine.

More bangs were heard Friday night as Atlantic City took the final step toward going live with ShotSpotter, a system that uses audio sensors to triangulate on a sound, determine whether it’s a gunshot, then record information such as time and number of shots.

The detection, qualification and validation analysis tested the sensors’ calibrations and quality of detection to help identify whether any re-calibration was necessary, Sgt. Monica McMenamin said. A decision was then expected to be made on when it would go live, which could be as soon as Saturday.

To test the system, a sequence of gunshots were made, using a bullet trap to ensure public safety. No bullets were fired into the air.

ShotSpotter has been a much-anticipated addition to the city’s crime-fighting technology, since gunshots often go unreported or reports come late enough to allow both suspects and victims to leave the scene.

With ShotSpotter, 911 dispatchers are notified in less than a minute of “validated gunfire incidents, even if no one calls 911,” McMenamin said. “By quickly notifying police with the precise information, ShotSpotter helps speed police response, has the potential to save lives, increases weapons-related arrests and enhances the safety of our neighborhoods.”

For more information, residents are invited to contact McMenamin directly at 609-442-5420 or email monicamcmenamin@acpolice.org Information is also available on the department’s Facebook page or via Twitter  @AtlanticCityPD.

Contact Lynda Cohen:

609-272-7257

Follow @LyndaCohen on Twitter