(CBS) — Forty police and firefighters were called to a subdivision in northwest suburban Hawthorn Woods in what police are now calling an elaborate hoax.

And they’re angry, WBBM’s Bob Roberts reports.

The caller told police he was 19 and he murdered his parents, held his sister hostage and would blow up a bomb.

Lake County Sheriff’s Sgt. Chris Covelli says it took authorities nearly three hours to determine it was a hoax.

“You have police officers risking their lives, driving lights and sirens to the scene, risking the lives of people on the street trying to get here quickly because they think they’re responding to a serious emergency. So, they’re taken away from other calls that they could be responding to.”

“The same with the fire department,” he adds. “They’re allocating resources. It becomes a major issue. It simply is not funny.”

If they find the prankster, that person could face a series of felony charges.