Aaron Williamson, a spokesman for the Bernalillo County Sheriff's Office, told AFP "multiple" weapons were found at the scene, including a "military-type assault rifle," adding that the investigation was still under way.
The police statement said a "male juvenile" is in custody, charged with two counts of murder and three counts of "child abuse resulting in death."
The identities of the suspect and the victims have not been made public. Local media reported that the suspect was 15 years old.
The shooting came days after US President Barack Obama unveiled a series of sweeping measures aimed at addressing gun violence in the wake of last month's school shooting in Newtown, Connecticut.
The proposed measures include a ban on some military-style assault rifles and closing loopholes that allow many gun buyers to avoid background checks.
The killing of 26 people at the Connecticut school, including 20 young children, has galvanized gun control advocates, but congressional opposition remains high to new restrictions on the constitutional right to bear arms.