A 15-year-old New Mexico teen accused of killing his 12-year-old playmate has been indicted on a murder charge.
A Valencia County grand jury indicted the teen on charges of first-degree murder and tampering with evidence.
Thirteenth Judicial District Attorney Lemuel Martinez said last week that he intends to try the 15-year-old as an adult.
An arrest warrant affidavit says the teen hit Alex Madrid, of Albuquerque, on the left side of his head, then placed him under a mattress in a rural field outside Los Lunas.
The teen told investigators he hit Madrid in self-defence because Madrid tried to stab him with a screwdriver.
Under New Mexico law, the state can charge minors as adults only if they are at least 14. The Associated Press doesn't typically identify juveniles charged in crimes.