Former Metropolitan Police officer David Carrick has admitted to 49 sexual offence charges, including 24 counts of rape.
In the nation's biggest-ever sex offence case, Carrick pleaded guilty to a 17-year campaign of abuse involving 12 women.
Speaking on the steps of Southwark Crown Court, officers leading the case thanked victims for their bravery in coming forward.
Iain Moore, the senior investigating officer, said he was relieved they would be spared the "ordeal of giving evidence" in court and see justice served.
Carrick will be sentenced over two days starting on 6 February.
Click here to sign up for our newsletters.