But detectives found the pieces of the note in the bin at his home and pieced them together to discover his chilling plans.
Lewis Ludlow, 26, who swore allegiance to Islamic State (IS), pleaded guilty to plotting to kill around 100 people outside the Disney store on London’s Oxford Street on Friday.
The paper scraps revealed “potential attack sites” including “madam tussauds”, “Oxford Street – busiest time…”, “St Paul’s cathedral” and a “Shia temple in Romford”.
It added: “Further locations scouted to kil. (sic)”
There were also details of a potential attack on Oxford Street using a van to mount the pavement.
It said: “Wolf should either use a ram attack or use…on the truck to maximise death…it is a busy street it is ideal for an attack. It is expected nearly 100 could be killed in the attack”.
In another letter he pledges allegiance to IS leader Abu Bakr al-Baghdadi, pledging to “live to serve as one of the soldiers…”.
It adds: “We will take revenge for we love death as you love life…”
In January, Ludlow, from Rochester in Kent, bought a ticket to fly to the Philippines and was stopped at the airport and his passport was seized.
He told police he was going to the country as a sex tourist.
But officers searching his home found he was in contact with a man named Abu Yaqeen in an area with a major IS presence.
Ludlow is currently being held at Belmarsh prison and will be sentenced in November.