CHICO, Calif. -

A married couple accused of murdering their 2-year-old adopted son was in court today and entered a plea of not guilty.

James and Evelyn Yhips were arrested on Jul. 19 for the murder of their son, “Benjamin,” who the district attorney believes died of blunt forced trauma to the head.

The defense is arguing that their son died of a genetic medical disease.

The couple adopted Benjamin from the Philippines.

Their trial date is set for Feb. 25.