Three weeks after turning 20, Jeffrey Andrew Hazelwood allegedly turned into a cold-blooded killer.

Police have offered no public explanation for why they believe Hazelwood shot and killed two 17-year-olds behind a Roswell grocery store, then stole a bank card and jumper cables. It's also not known whether Hazelwood knew the victims, Natalie Henderson and Carter Davis, before shooting them each once in the head.

Public records do not reflect that Hazelwood had ever been accused of a violent act before this summer. But court documents and years-old Roswell police reports suggest that Hazelwood’s childhood was marked by behavior problems, disobedience and disputes between his mother and the grandparents who raised him.

Hazelwood was arrested Aug. 3, about 48 hours after he allegedly killed Henderson and Davis. He has been charged with murder, and in a first court appearance, shook uncontrollably and appeared to be mumbling to himself, sometimes staring into the air. Zimmerman, the attorney, attributed his client’s behavior to nervousness.

Hazelwood’s next court hearing is scheduled for Aug. 19.

Read more on Jeffrey Hazelwood's childhood at myajc.com.