Christian gender justice specialist Natalie Collins says there must be a "whole culture change" within the Met after the brutal murder of Sarah Everard.
Wayne Couzens was a serving firearms officer when he made a fake arrest to kidnap Everard, 33, off a London street before raping and murdering her in an hourslong ordeal.
He was given a whole-life sentence at the Old Bailey on Thursday.
Collins said his crimes were so "horrific" that they "deserve" the full life sentence, but also expressed frustration that her death "could have been prevented".
"His kidnap, rape and murder of Sarah Everard was torturous and compounded by him using his position as a police officer to kidnap her," she said.
"The torment to Sarah's family and friends is horrendous. The terror to women and girls everywhere knowing that police officers may not be safe is something that Black and minoritised men, women and children have had to deal with for far too long."
Grim details to have emerged about Couzens include allegations of sexual harassment by female colleagues and an apparent nickname of "the rapist" among colleagues at the Civil Nuclear Constabulary, where he worked prior to the Met.
There have been calls for current Met commissioner Cressida Dick to stand down after reports that Couzens allegedly shared offensive WhatsApp messages with other officers, and was linked to indecent exposure claims that the police were aware of.
"It is horrifying to know that Sarah's muder could have been prevented if bystanders had spoken out, if police culture had a zero tolerance for abusive men and if his female colleagues had been listened to," said Collins.
"So much needs to change, but that cannot happen while the Metropolitan Police continue to suggest the issues are about individual officers and not a whole culture that needs to change."
Nicole Jacobs, the UK's domestic abuse commissioner, fears there are more Wayne Couzens in the force.
"The police can't respond to this by saying: 'Don't worry, this is just an isolated problem'. They cannot take the view this is one terrible example," she told The Independent.
She added: "It is not about one bad apple. The murders of Sarah Everard, Bibaa Henry, Nicole Smallman, and Sabina Nessa need to be placed in this wider context of failure.
Ex-Met Ch Supt Parm Sandhu told BBC Radio 4's The World at One that the police service is "very sexist and misogynistic", and female officers are afraid to report male colleagues.
"A lot of women will not report their colleagues," she said.
"What happens is that male police officers will then close ranks and the fear that most women police officers have got is that when you are calling for help, you press that emergency button or your radio, they're not going to turn up and you're going to get kicked in in the street.
"So you have got to be very careful which battles you can fight and which ones you can actually win."
Sir Thomas Winsor, Her Majesty's Chief Inspector of Constabulary for England and Wales, defended Dame Cressida in comments to BBC Radio 4's World at One.
"Cressida Dick is not responsible for the individual acts of every police officer, including a police officer of the appalling criminal proclivities and intent of Wayne Couzens," he said.
"Cressida Dick has a great deal of support from her officers and has led the Metropolitan Police with distinction. Not everything in the Met is good and we have published many reports that are critical of the Met, but this is not a case for the resignation of the commissioner."