The End of a Mystery 2003 on netflix

Joaquin comes back to Granada in the eighties trying to find out about something happened when he was a child and the Spanish Civil War was going on. He helped an unknown man who survived after being executed. He finds the man, Galapago, who is now quite old, poor and with almost no memory. Joaquin takes care of him and finds hints that point to Galapago as Federico García Lorca.