Senior, a television newscaster and English teacher, was assassinated while photographing looting by soldiers in a public market in the aftermath of a coup begun two days earlier by then-second prime minister Hun Sen. He was accosted by the soldiers, Hun Sen loyalists, who shot him first in the knee. As he lay in the street pleading for mercy, he was shot again, executed in front of his Cambodian wife and brother-in-law.
The 23-year-old Canadian citizen was born in Cambodia, where he was orphaned as an infant during the Pol Pot terror years. In 1975, he was adopted by a family in Canada, where he was raised. He returned to Cambodia in 1995. He had earlier worked at the Cambodia Daily in Phnom Penh. Phnom Penh editors say that Senior's pictures, had they been recovered, would have been used in their coverage of the coup.