OXNARD, Calif.—Ventura County medical examiners say a 26-year-old man was high on amphetamine when he died of asphyxia in police custody this year.

The Ventura County Star reports ( http://bit.ly/TlCRSN) an autopsy for Robert Ramirez found an extremely high level of methamphetamine in his blood, and even more in his stomach.

Officials say Ramirez suffered cardiac complications from restraint-related stress and his death is categorized as a homicide, but that only means death "at the hands of another" without implying intent to cause harm.

On June 23, police responded to a call from a friend who feared Ramirez was overdosing after he swallowed bags of meth and marijuana.

Coroners say a struggle ensued, leading to Ramirez to be restrained prone, with handcuffs and leg restraints, before he died of a heart attack.