Updated

Sheriff's officials discovered a couple fatally shot in their Houston-area home after a high school principal called the couple's 14-year-old grandson to ask why he wasn't in school.

The teenager is being held on two counts of capital murder.

Chambers County Sheriff Brian Hawthorne said in a statement Wednesday that the boy indicated to the principal that his grandmother was having a medical emergency. The principal told his staff to call 911 and emergency responders found the couple Tuesday at their home in Beach City, 30 miles east of Houston.

Investigators believe the couple was killed late Sunday or early Monday.

The Associated Press is not naming the grandparents, both 72, because it could identify the juvenile suspect.

Investigators have not released a motive for the shooting.