Updated

French authorities have detained a 48-year-old Frenchman in connection with the grisly shooting death of a British-Iraqi man and three others in the French Alps nearly 18 months ago.

State prosecutor Eric Maillaud of the eastern city of Annecy said the man was detained Tuesday following witness accounts after authorities issued a sketch of a possible suspect wearing a helmet in November.

Maillaud's office suggested in a statement that the arrest could be followed by others. Maillaud said the man was presumed innocent and was being held for questioning.

Saad al-Hilli, his wife, an elderly relative and a cyclist were killed in the attack near Annecy in September 2012. The couple's two young daughters survived, including one who spent about eight hours huddled beneath her mother's lifeless body.