Convicted Roswell Publix murderer Jeffrey Hazelwood used a cell phone to take his picture inside the prison where he is serving a life sentence, the Georgia Department of Corrections said late Tuesday. But investigators aren’t sure how he got the phone, a spokeswoman said.

A picture of Hazelwood was posted last week on Instagram, though electronic recording devices are not allowed in prisons.

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The Atlanta Journal-Constitution contacted the DOC about the picture and an investigation was launched. However, investigators were not able to locate the picture on the social media app. The AJC provided a screen grab of the post to a department spokeswoman.

The “selfie” was posted Thursday afternoon using the “insta story” on Instagram, meaning the post remained on the app for 24 hours. Shortly after noon Friday, the picture was gone. Early Wednesday, a DOC spokeswoman told Channel 2 Action News Hazelwood would face disciplinary action.

In May, Hazelwood pleaded guilty but mentally ill to murdering two teenagers behind a Roswell Publix and was sentenced to life in prison without the possibility of parole. Hazelwood, 21, is currently at Baldwin State Prison in Milledgeville.

State corrections officials have spent millions in an ongoing struggle to keep contraband, including cellphones, out of prisons. Nearly 22,000 “incidents” that involved wireless devices were reported in state prisons, halfway houses and other state-overseen correctional facilities between 2012 and last year, according to data the DOC provided earlier this year. The incident data covers fights, prison riots, discoveries of contraband and other disturbances.

The annual number of incidents involving contraband cellphones dropped to 3,900 last year, down from more than 5,000 in 2015.

Channel 2's Liz Artz reports.