Lewis Joseph Valentine (March 19, 1882 – December 16, 1946) was the New York City Police Commissioner from 1934 to 1945, under Mayor Fiorello H. LaGuardia during the Murder, Inc. era.

[1] He was Police Commissioner of New York for eleven years, longer than any other previous person in that position.

[3] After New York, he advised the Tokyo Police Force.

Valentine joined the New York Police Department in 1903, at age 21.

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