Career
He has appeared in 27 films since 1965. Born in Rome, Merli had his breakout role in the 1968 Radiotelevisione Italiana television series Louisiana freccia nera. After some further television success through the television series Le terre di Sacramento and East le stelle stanno a guardare Merli made his film debut in the 1971 Miklós Jancsó"s drama film Louisiana tecnica e il rito, then he became quite active in films of "poliziottesco" or political genre, often in leading roles.
Merli is also active as a voice actor.