Valter was born in Prijepolje (present-day Serbia) in 1919. After completing his economics degree, he began to work in a Sarajevo bank in 1940. During this time, he joined the Communist Party Committee for the city of Sarajevo. During the war, he stayed in Sarajevo until 1942, when he escaped to the liberated territories controlled by Partisans. He subsequently became a deputy commander of the Zenica Partisan detachment. Later on, he became the commander of a battalion in the 6th Eastern Bosnian brigade. In 1943 he was ordered to return to Sarajevo and to take command of an underground partisan group which was tasked to drive out any Axis powers from the city.
Valter was killed by a mortar grenade in the fighting on the day of Sarajevo's liberation, April 6 1945. He has since become something of a city icon, having the film Valter brani Sarajevo (Walter defends Sarajevo) named after him.