A teen accused of killing his 5-year-old Atlantic foster brother last year would throw things and hit inanimate objects during temper tantrums. The Omaha World-Herald says 18-yearold Cody Metzker-Madsen‘s foster mother said in a 2011 email, that he didn’t understand the difference between right and wrong when he was playing and that he didn’t comprehend that if he copied the wrestling moves he saw on TV, that it could hurt him or someone else. Even so, 53-year old Julie Coolman, of rural Logan, said she didn’t believe Cody was a threat to her family. She said he was never aggressive toward them.

The testimony came Tuesday during the first day of Metzker-Madsen’s first-degree murder trial in the death of Dominic Elkins. The teen has pleaded not guilty. Prosecutors say Metzker-Madsen, who was 17 at the time, killed Dominic as the two were playing outside Aug. 31, 2013.

Dominic’s body was found in a wooded ravine. An autopsy determined that he died from blunt-force head injuries and drowning. Dominic’s mother earlier this month sued the Coolmans, accusing them of negligence in her son’s death.The lawsuit filed by Dominic’s mother accuses Don and Julie Coolman of failing to properly care for and supervise Dominic and Metzker-Madsen; failing to protect Dominic from harm or unreasonable risk of injury; failing to respond quickly to the incident and Dominic’s injury; and leaving the boys in the care of a juvenile female.

Julie and Don Coolman were away from home at the time of the attack alleged by authorities, leaving the two boys under the supervision of one of the Coolman’s twin daughters; the girl was 12 at the time.

Metzker-Madsen’s attorney is using an insanity defense. Public defender Michael Williams contends that his client suffers from “certain mental health disorders.” Earlier this year, a psychologist and a psychiatrist who examined Metzker-Madsen testified that he showed symptoms of attention deficit hyperactivity disorder, oppositional defiant disorder and fetal alcohol syndrome. The psychiatrist, Dr. Arnold Andersen, said in a hearing in April that Metzker-Madsen’s mother used methamphetamine while pregnant with him.