soon after they moved, he entered the election for marquette county prosecuting attorney in 1934. voelker was the only local resident to campaign for the office, and when he was elected later that year, he was the first democrat to hold the office since the american civil war. he maintained a private law practice while serving as prosecutor and also served in other capacities. he was a member of the marquette county bar association, serving as association president from 1939 to 1941. during the 1940s and 1950s, he served on several committees of the state bar of michigan, including the committee on judicial selection and tenure and the committee on criminal jurisprudence. voelker was a member of the state board of law examiners from 1942 to 1945, and he was the city attorney for ishpeming in 1943 and 1944. he also assisted the michigan attorney general in 1943 with a bribery investigation of the michigan legislature.