A 20-year-old Cobb County man was sentenced to 20 years, including 12 to serve in prison, for putting a boy in a headlock and stealing his iPod, the district attorney said Monday.

Shareef Tawwab Hakim, of Marietta, was convicted of robbery and aggravated assault, DA Vic Reynolds said.

The teenage victim was sitting outside his Bellmeade Drive apartment around 9:30 p.m. on Oct. 22, 2013, when he was approached from behind by Hakim, according to investigators. Hakim put the boy in a headlock and took his iPod, the DA said.

Hakim was arrested in November and booked into the Cobb jail, where he has been held without bond, booking records showed. During his trial, he took the stand and admitted he took the iPod before being convicted Thursday in Cobb County Superior Court.

“He is violent, and this is all a joke to him,” Assistant DA Jaret Usher told Judge Robert D. Leonard II. “His demeanor demonstrates that.”

Leonard sentenced Hakim to a term of 20 years, with 12 years to serve in prison and the rest on probation, Reynolds said.