In 1968, Beach Boy
Dennis Wilson introduced Melcher to ex-con and aspiring musician
Charles Manson. Manson and his "family" had been living in Wilson's house at 14400
Sunset Boulevard after Wilson had picked up hitchhiking Manson family members
Patricia Krenwinkel and Ella Jo Bailey. Wilson expressed interest in Manson's music and also recorded two of Manson's songs with the
Beach Boys. For a time, Melcher was interested in recording Manson's music as well as making a film about the family and their hippie commune existence. Manson met Melcher at
10050 Cielo Drive, the home that Melcher shared with his girlfriend, actress
Candice Bergen and musician
Mark Lindsay. Manson eventually auditioned for Melcher but Melcher declined to sign him. There was still talk of a documentary being made about Manson's music but Melcher abandoned the project after witnessing Manson fighting with a drunken stuntman at
Spahn Ranch. Soon after, Melcher and Bergen moved out of the Cielo Drive home. The house's owner, Rudi Altobelli, then leased it to film director
Roman Polanski and his wife, actress
Sharon Tate. Manson was reported to have visited the house on more than one occasion asking for Melcher but was told that Melcher had moved. Melcher's former roommate Mark Lindsay stated that "Terry and I talked about it later, and Terry said Manson knew (that Melcher had moved) because Manson or someone from his organization left a note on Terry's porch in Malibu." In reviewing police files and other data, O'Neill found evidence that Melcher was associating with Manson during the four month period after the Tate-Labianca murders, but before Manson was arrested. Bugliosi had seemingly hidden these documents, which undermined claims that the Tate murders had been intended to frighten Melcher, and as revenge for his refusal to record Manson's music. O'Neill also found documents indicating Melcher was
having sex with a 15-year-old Manson family member,
Ruth Ann Moorehouse. Dean Moorehouse – Ruth Ann's father and a Manson Family member – had also resided at 10050 Cielo Drive with Melcher.
Tex Watson was known to frequently visit the residence. ==Later years==