Chinatown, Water, murder felony crimes & incest

In 1937, a woman posing as Evelyn Mulwray hires private investigator J.J. "Jake" Gittes to trail her husband Hollis under the ruse that she suspects him of infidelity. After Gittes photographs Hollis in the company of a young woman, the pictures appear in the Los Angeles Times with a story exposing their supposed "love nest." Gittes is confronted by the real Evelyn Mulwray, who threatens to sue him after her imposter used him to discredit Hollis, chief engineer at the Los Angeles Department of Water and Power.

Gittes visits a reservoir where he sees his former colleague, LAPD Lieutenant Lou Escobar, as Hollis's dead body is dragged from the water. Evelyn officially hires Gittes to investigate Hollis's death as a homicide. He finds that huge quantities of water are being released from the reservoir every night, despite a drought. He is warned off by Water Department Security Chief Claude Mulvihill and is attacked by his henchman, who deeply cuts Gittes' nose with a switchblade. The next morning, Gittes receives a call from Ida Sessions, the woman who posed as Evelyn Mulwray. She refuses to say who hired her but tells him to check that day's obituaries.

Gittes learns that Hollis once privately owned L.A.'s water supply with his wealthy father-in-law and former business partner, Noah Cross, until a bitter feud. Cross offers to double Gittes' fee if he finds the girl who disappeared after the "love nest" story was published.
https://en.wikipedia.org/wiki/Chinatown_(1974_film)
https://en.wikipedia.org/wiki/John_Huston
https://en.wikipedia.org/wiki/Anjelica_Huston
https://en.wikipedia.org/wiki/Jack_Nicholson

In 1974 Jack Nicholson, 37 & Anjelica Huston, 23 were living together at 12850 Mulholland Drive, named after self-taught soil engineer William Mulholland, the man who brought water to Los Angeles.

1974 Musical score from the Paramount Pictures film:
https://www.bing.com/videos/riverview/relatedvideo?q=Forget%20it%20Jake,%20It%27s%20Chinatown%20clip&mid=4D7A48C75E1CEC6E62444D7A48C75E1CEC6E6244&ajaxhist=0