At the End of the Night 1992 on netflix

Robert Tanner is a popular, courteous grocer in the provinces. No one believes the unassuming man to be malicious. And yet Tanner is seething. One night, out of the blue and with a strange calm, he kills first his wife Edith and then his young son Beni. The next morning, he leaves the place of horror with a strange feeling of liberation. On his “journey” he reveals himself to a strange woman and wants to face the press.