A serial stalker who bludgeoned a Finnish student to death after attacking three other women on the same day has admitted carrying out a "horrific" rape two years earlier.
Jason Dockrill is currently serving a life sentence for the "sadistic and sexual" murder of 23-year-old Suvi Aronen.
She was raped, mutilated and bludgeoned to death near Wanstead Common, east London on March 20, 2003.
Dockrill, 46, pleaded guilty at the Old Bailey on Monday to rape and two counts of indecent assault relating to an attack on a stranger in a park in November 2001.
Judge Timothy Pontius adjourned sentencing until July 18 so that mental health reports can be carried out.
He said: "Plainly, having read the statement of the victim, this is a very serious sexual attack. She was in fear for her life.
"It was a stranger rape carried out in a park and it consisted not just of rape but two serious indecent assaults as well.
"It is fortunate the defendant has decided to change his plea today and saved the victim the ordeal of giving evidence about these horrific crimes committed 15 years ago."
Dockrill was linked to the attack by DNA evidence after a cold case review, the court was told.
When sentencing him to life imprisonment with a minimum of 25 years for the murder in 2004, Judge Michael Hyam said he was "a danger to women and likely to remain so for a long time, if not indefinitely".
The unemployed fitter, from Stratford, east London, had denied murdering Ms Aronen on the grounds of diminished responsibility but was convicted of murder after trial.
The judge described the attack as "sexual and sadistic conduct so brutal that doctors consider it exceptional".
Dockrill dragged Ms Aronen into scrubland as she walked home, sexually assaulted her and battered her with a brick.
Her harrowing cries were heard by her parents who had called her mobile phone just as he struck.
Dockrill had attacked three other women in the hours leading up to Ms Aronen's death - he tried to rob a 44-year-old woman, attacked an 80-year-old in the park and violently robbed another woman in the street.
He was jailed for a total of nine-and-a-half years for these, to run concurrently.
Additioinal reporting by Press Association.
