Police say swatting is a serious crime that wastes valuable resources – and it's on the rise across the country.

Former Fairfield Police Chief Gary McNamara told News 12 Connecticut that all threats have to be responded to as if they're real, but there are tell-tale signs law enforcement can look for to see if a threat is likely swatting.

"Is the call blocked? Is the call lacking of details? Do they pronounce the streets in the correct way? Do they give signs they really don't know the business at all? And if it's reported to be an active incident, are you getting other calls? Very few incidents occur where you only get one call," he said.

News 12 Connecticut’s Sean McCabe was at Staples High School in Westport – one of multiple schools that were the victim of swatting Friday morning.

Staples High School students said they had to shelter in place for over an hour as police cleared the building of threats.

"My class went and huddled in the corner, we turned off the lights. Our doors lock automatically, that was an update after Sandy Hook," said senior Julia Weber. She spent 45 minutes convinced there was a shooter in the building.

The phony threats came in as thousands of state and local police gathered in East Hartford to mourn their fallen comrades from Bristol.

"There's a major statewide event that's occurring, involving a large amount of law enforcement officers. At that particular moment, now we start to get these reports of an active shooter or a bomb threat occurring," McNamara said. He added that swatting is a serious crime because police have to investigate the threats.

"These incidents drain resources and require a response. You have to treat all of these that they're real until you determine that they're not real," McNamara said but added that there are clues police and operators can look out for to try and identify a swatting call.

"An incident like an active shooter is going to generate a lot of calls. If you only have gotten one call on the incident, that's something that you want to be aware of," he said.

McNamara said a 2015 swatting incident in Fairfield, while he was still police chief, forced officials to lock down all 17 schools in town.