A sex killer, serving life for battering a Finnish student to death in Wanstead in 2003, has also admitted a “horrifying” stranger rape two years earlier.

Jason Dockrill, 46, evaded capture after he attacked a woman in a park in the City of London between November 2 and 5, 2001.

He was linked to the rape last year following a cold case review of the original investigation.

Dockrill had already been convicted for the brutal murder of Suvi Aronen in Wanstead Park in March 2003.

He killed the 23-year-old as her distraught mother heard her pleas for help from 1,000 miles away over a mobile phone.

Dockrill left her body horrifically mutilated after a chance encounter with the student in an underpass in during a series of attacks on women.

When he was told he was being arrested for murder Dockrill, formerly of West Road, Stratford, said: “Yeah, I’m loving it.”

The ex-building engineer, described as a shy loner, was jailed for a minimum of 25 years after being found guilty of the murder in April 2004.

On Monday he admitted one charge of rape and two counts of indecent assault for the 2001 rape at the Old Bailey via a video link from Belmarsh Prison.

Prosecutor Anita Arora said: “He is currently serving a minimum sentence of 25 years for the murder itself and other concurrent sentences for physical assaults on women the same day as the murder in 2003.”

Referring to the DNA techniques that led to the his arrest for the earlier sex attack, she said: “It’s a classic cold case my Lord.

“As the scientific technique became more sophisticated and became more able to detect lower levels of DNA they [police] were able to trace the defendant.”

Judge Timothy Pontius adjourned sentencing until July 18.