Caleb Flynn -- who auditioned for "American Idol" in 2013 -- is back in the limelight but for all the wrong reasons ... he's just been arrested for allegedly murdering his wife.

Flynn was apprehended Thursday by the Tipp City PD in Ohio and booked into the county jail for murder, felonious assault and tampering with evidence, according to official records. Caleb also posed for a mug shot with no expression on his face.

Police say they discovered his wife Ashley's body inside the couple's Tipp City home, just north of Dayton, after cops received a report of a burglary at the residence.

Authorities say Caleb shot 37-year-old Ashley using a 9mm semiautomatic handgun and then staged the crime scene, leading officers astray.

WHIO-TV obtained dispatch logs that described the moment officers arrived at the scene, believing someone had broken into the home. The dispatcher warned the alleged prowler might still be there, and the "garage door is open."

During Season 12 of "American Idol," Caleb didn't make the cut during his audition ... but he did give an interview as part of his trial, in which he gushed about his love for music -- and his wife.

This is a developing story.