Mel Willmirth was born in Coalinga on June 3, 1914, the son of an oil fields mechanic. He was raised there and educated locally.
He left high school before graduation to work in the oil fields. In the late 1930's he was hired as a police officer by the City of Coalinga. In 1942, he was appointed Superintendent of the Fresno County Industrial Road Camp, located in the Coalinga area.
Granted a leave of absence by the county, he served three years in the U.S. Navy during WWII, returning to the superintendent's job after his discharge. In 1954, he was elected Fresno County Sheriff, defeating the tainted incumbent, Joseph Tracy. Willmirth easily retained his position in the next four elections. He was unseated in the contentious 1974 election by Guy Langley. He died in Fresno on December 6, 1979, survived by his wife, Pauline, a son and daughter.
During Sheriff Willmirth's watch the sheriff's department moved into the era of modern policing. Under his leadership the sheriff's department became one of the first in the state requiring that applicants for deputy sheriff have some college credits. He instituted 24-hour patrol coverage in the unincorporated areas. In 1959, he formed the Sheriff's Underwater Rescue Unit. In 1968-69 the modern Sheriff's Administration Building was built on the north side of the Courthouse Park, facing Fresno Street. In 1972, the countywide constable system was abandoned, and 30 constables and deputy constables were consolidated into the sheriff's department.
Willmirth had extensive experience in detentions before becoming sheriff, and he oversaw many changes at the department in the correctional field. As superintendent of the Coalinga road camp, Willmirth worked directly under the Board of Supervisors. Upon his election as sheriff, the Coalinga camp and a similar facility at Kearney Park were placed under the authority of the sheriff's department. In 1959, the county purchased 400 acres at Elkhorn and Elm, constructing the Elkhorn Industrial Farm. The road camps in Coalinga and Kearney Park were subsequently closed. At the time the new jail was constructed in 1941-43, the pre-1941 jail, parts of which dated to the late 19th and early 20th centuries, was closed. Due to post-war growth and population expansion in the county, the old jail had to be reopened in 1948, giving service until 1959, when it was demolished. A new wing was constructed at the jail in 1960, and other major renovations were made in the early 70s. In 1971, the sheriff created the position of Correctional Officer, permanent professional jail officers, who replaced the deputy sheriffs who had staffed the jail previously.
Among the major crimes solved during Willmirth's terms in office was the 1957 investigation into the missing farm worker, Francisco Oliva. Oliva had been murdered and buried on a Firebaugh area ranch in 1946, but it wasn't until 1957 that his family in Mexico realized that he was missing. Within three months of a report being filed, detectives had arrested the suspect and recovered the victim's remains. In March 1961, the owner of Liquor Junction, in Highway City, was murdered during a robbery. Three months later detectives arrested the four suspects. In July 1962, James Abner Bentley was executed for the crime in San Quentin's gas chamber.