Weiss was born in
Baton Rouge to physician Carl Adam Weiss and the former Viola Maine. Weiss' father was a prominent
ophthalmologist who had once treated Senator Long. His paternal grandfather was an organist and choirmaster in
Bavaria before he emigrated to
Louisiana in 1870. His mother had French and Irish ancestry. Both of Weiss' parents were Roman Catholic, although he might have had some
Jewish ancestry through his paternal grandfather. However, despite the
conspiracy theories promoted by the
antisemitic preacher and Huey Long ally
Gerald L. K. Smith, after Long's death, there is no evidence that his family remained religiously Jewish. Weiss was educated in local schools and graduated from
St. Vincent's Academy, a Catholic school. Growing up, Weiss had an interest in electricity and mechanics. He once tampered with the lock at the
pew of his downtown church, locking his mother and two aunts inside. Initially, he studied engineering at university, his father having discouraged a career as a doctor due to its time commitments; he often went to the early 5:15 a.m. mass in case of a later medical emergency. However, after two years, Weiss switched to studying medicine, obtaining his bachelor's degree in 1925 from
Louisiana State University in Baton Rouge. He did postgraduate work in
Vienna,
Austria, and briefly practiced at the
American Hospital of Paris. Weiss thereafter was awarded internships in Vienna and at
Bellevue Hospital in
New York City. It was while in Europe that Weiss bought a
FN Model 1910 pistol for $25 (equivalent to approximately $ in ) that he allegedly used in the Long assassination. In 1932, he returned to Baton Rouge to enter private practice with his father. He was president of the Louisiana Medical Society in 1933 and a member of the
Kiwanis International. ==Suspected assassination of Huey Long==