Nelson subsequently acquired a job working as a janitor at St. Mary's Hospital, using the pseudonym "Evan Louis Fuller." There, he met 60-year-old Mary Martin, an administrative worker. The two began to date, and were married in August 1919. Their marriage, however, was short-lived, as Nelson "made her life a living hell" with his jealous rages, bizarre sexual demands, religious delusions, and increasingly violent behavior, leading her to separate from him after cohabiting for only six months. Martin would later recall various bizarre behaviors she witnessed while living with Nelson, which included protracted disappearances from their home and unusual bathing practices that entailed him pouring glasses of water over his toes.