David Berkowitz aka The Son Of Sam .44 caliber serial killer who from 1976 through the summer of 1977 terrorized New York City killing six people and wounding seven others before his capture in July 1977.

Vintage prison mailed envelope postmarked Oct. 1, 1979 which predates his conversion to Christ.
Hand signed on the front, David Berkowitz, with his prison number handwritten below his name.

David Berkowitz Signed Envelope 1979