Suspect in 'American Idol' Killings Used Couple's Gun To Shoot & Then Called Police

Cops say the suspect who killed an "American Idol" music supervisor and her husband turned their own gun on them -- before calling the police on himself.

L.A. County D.A. Nathan Hochman dropped the bombshell Monday night at a town hall in Encino ... revealing 22-year-old suspect Raymond Boodarian not only used the couple’s gun but then dialed 911 on his own cell, gave cops his name, and basically handed them the trail to track him down.

As we’ve reported ... Boodarian’s accused of breaking into Robin Kaye and Thomas Deluca’s Encino home earlier this month. The couple came back mid-burglary and, in a deadly twist, were allegedly gunned down during a confrontation with him.

Our law enforcement sources told us at the time authorities recovered a handgun at the scene ... which they were testing to determine if it belonged to the victims or the suspect.

As we've reported, cops discovered the couple’s bodies with gunshot wounds during a welfare check ... and by the next day, they had Boodarian in cuffs outside his home, with photos showing a massive police response.

Raymond’s now facing two counts of murder and a burglary charge for the deadly break-in.