Born in Mainz-Kastell on 11 August 1889, Walter Fritsch participated in World War I as an artillerist and airman. In 1922 he worked as trainer at the police sports school in Spandau. In February 1933 Fritsch was appointed head of the newly formed Field Police. Under his command the barracks in General-Pape-Strasse became the seat of the early concentration camp. When the Field Police Force was converted into the Feldjägerkorps in October 1933, Walter Fritsch continued to head the unit. After the dissolution of the Feldjägerkorps in the spring of 1935, it was discovered that Walter Fritsch had embezzled money and kept illicit bank accounts. He had also arrested people who knew about his embezzlement. Court proceedings of the Gau against him in this matter were dropped for political reasons.
In 1941 Walter Fritsch had to resign from the Nazi Party because it came out that his grandmother was Jewish.