Senior Superintendent Antonio Interia, Masbate police director, said alleged triggerman Rolando Boncaras was cornered at the Acacia nursery here.
NBI director Reynaldo Wycoco earlier named Boncaras, said to be a jail guard, Isagani Quidato and Alexander Bermoy as the ones who gunned down Espinosa during a dance in the coastal village of Bantigue past midnight of Aug. 9.
Quidato is the brother of provincial jail warden Charles Quidato.
At least three witnesses positively identified Boncaras during a police line-up.
Meanwhile, operatives of Task Force Espinosa, armed with a search warrant, raided the compound of former vice mayor Florencio Fernandez here last Friday afternoon and picked up two men.
Arrested were Prosperio Losantas and Onyor Saragoza. They were, however, later released and placed under their lawyers custody after witnesses failed to positively identify them as accomplices in the Espinosa murder.
Fernandez ran against Espinosa in the recent mayoral elections, and has a pending electoral protest with the Commission on Elections. His brother, the late governor Jolly Fernandez, was gunned down near his residence in 1989.
Three other persons were killed and four others were wounded during the attack on Espinosa. Celso Amo, Cet Dematera and Jaime Laude