OUAGADOUGOU, April 6 (Reuters) - Burkina Fasos former president Blaise Compaore was sentenced to life imprisonment for complicity in the 1987 murder of his predecessor Thomas Sankara, a military tribunal ruled on Wednesday. The charismatic Marxist revolutionary was infamously gunned down in the West African nations capital Ouagadougou at the age of 37, four years after he took power in a previous putsch. Compaore was charged in absentia along with his former head of security Hyacinthe Kafando, who was also sentenced to life imprisonment. Both have previously denied any involvement in Sankaras death. The former president went on to rule for 27 years before being ousted in another coup in 2014 and fleeing to Côte dIvoire.