A former Lord Of The Rings visual effects technician has admitted killing his parents at their home in Kensington after a row over his dog Enzo.
Sergey Koudryavtsev, 48, stabbed his mother Tatiana, 68, and father Vladimir, 69, at the family home in Appleford Road, west London, on May 20.
Former university lecturer Mrs Koudriavtseva and her husband were found dead three days later after the defendant called police.
The defendant, who has dual Russian and New Zealand nationality, had argued with his parents over the care of his Mastiff dog.
At a hearing at the Old Bailey at which he represented himself, Koudryavtsev entered guilty pleas to the murders.
The court heard psychiatric reports had found he was fit to stand trial and enter pleas.
One report found that he acted out of “anger and rage” linked to his personality structure where he put his needs before any empathy towards his parents.
Judge Nicholas Hilliard QC also questioned the defendant about whether he accepted what he had done.
Addressing the dock, Judge Hilliard said: “You know what the allegations are against you. Do you accept that you did kill your parents, both of them?”
The defendant said: “Yes, I accept responsibility for that.”
The judge went on: “When you did what you did, was it your intention to kill them?”
He replied: “Yes. When I did it that was my intention.”
The judge said: “Do you understand that if you had lost control when you killed them that could reduce the offence of murder to the lesser offence of manslaughter?”
Koudryavtsev said: “I understand the concept but I believe I was in control.”
The defendant said he had considered killing his parents for three-and-a-half months as a “deterrent” but added: “I cannot say I was really planning. If you asked me the day before whether I would do it or not, I would say no, definitely not.
“On the day I did it, I was fully conscious that was what I was doing.”
Prosecutor Anthony Orchard QC told how Koudryavtsev called police on May 23 saying he wanted to “surrender himself for murder”.
He said he had killed two members of his family and gave the address.
Officers arrived at the home in Adair Tower and found his mother dead in the bath fully clothed and his father’s body in the bedroom. They had both been stabbed.
Judge Hilliard adjourned sentencing until October 11.