New Mexico teen indicted in 12-year-old's killing

LOS LUNAS, N.M. - A 15-year-old New Mexico boy accused of killing his 12-year-old playmate was indicted Thursday on a murder charge.

A Valencia County grand jury indicted the teen on charges of first-degree murder and tampering with evidence.

An arrest warrant affidavit said the 15-year-old hit Alex Madrid, of Albuquerque, on the left side of his head, then placed him under a mattress in a rural field at Meadow Lake, an area about 40 miles south of Albuquerque. The boy's body was found last week in the field littered with trash and old tires in a rural, unincorporated area near Los Lunas.

Sheriff Louis Burkhard said Madrid appears to have died from severe trauma.

The teen told investigators he hit Madrid in self-defense because Madrid tried to stab him with a screwdriver following an argument over the suspect's infant daughter, the affidavit said.

Deputies said the 15-year-old suspect has a baby girl who is 4 months old.

Thirteenth Judicial District Attorney Lemuel Martinez said last week that he intends to try the 15-year-old as an adult. But he said a judge would have the option of sentencing the teen as a youthful offender. That means the judge wouldn't have to impose a maximum sentence if the boy is convicted.

Under New Mexico law, the state can charge minors as adults only if they are at least 14. CBS News typically doesn't identify juveniles charged in crimes.

At a recent detention hearing, Cindy Mercer, the suspect's attorney, denied the allegation that the teen killed the 12-year-old and suggested her client can't comprehend what's happening.

"Due to his low mental functioning, I don't believe he understands the charges or his rights," she said.