de Mohrenschildt. A shady international type who befriended the Oswalds in Texas. Set them up with the local Russian emigre community. But Oswald and De “knew” each other. Poppy’s Texas address was found in DeMorenchildt’s address book when he was found murdered in 1977.
Per Wiki:
“Mohrenschildt received a business card from Gaeton Fonzi, an investigator for the House Select Committee on Assassinations, telling him that he would like to see him.[57] The HSCA considered him a "crucial witness".[58] That afternoon, Mohrenschildt was found dead from a self-inflicted shotgun wound to the head in a house where he was staying in Manalapan, Florida.[59] The coroner's verdict was suicide.[60]
en.m.wikipedia.org/wiki/George_de_Mohrenschildt