Court documents say a 15-year-old New Mexico boy accused of killing his 12-year-old friend struck him following an argument over the teen's infant daughter.
The arrest warrant affidavit, first obtained by KRQE-TV, says the 15-year-old suspect hit Alex Madrid, of Albuquerque, on the left side of his head, then placed him under a mattress in a field outside Los Lunas.
Valencia County Sheriff's Capt. Gary Hall says the suspect's daughter is around 4 months old.
The suspect told deputies Madrid had tried to stab him with a screwdriver. He has been charged with first-degree murder and tampering with evidence.
The teen's attorney, Cindy Mercer, didn't immediately return a phone message from The Associated Press.
Under New Mexico law, the state can charge minors as adults only if they are at least 14. The AP typically doesn't identify juveniles charged in crimes.
Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.