Yousef Makki 'filmed killer's knife jokes on Snapchat'
A grammar school student filmed a teenager who later stabbed him to death joking about knives, a jury was told.
Yousef Makki, 17, was killed in March after he and two friends arranged to buy drugs and intended to rob the dealer, Manchester Crown Court heard.
Boy A, the alleged killer, and Boy B, both 17, deny charges relating to his death in Hale Barns, Cheshire.
Jurors were also shown videos of Boy A playing with a huge knife and pretend to slash someone across the neck.
The teenagers on trial cannot be named for legal reasons due to their age.
Manchester Grammar School student Yousef was stabbed by Boy A - who denies murder claiming it was self-defence - on 2 March.
He has previously told the court he was upset with Boy B and Yousef after being "jumped" by others and a row developed where Yousef pulled a knife on him.
The jury was shown videos and messages recovered from Yousef's Snapchat account.
In an undated clip Yousef filmed Boy A joking about "shanks" - slang for knives - with the former smiling back at him.
Another video sent from Boy B to Yousef four days before his death showed a knife identical to the one used to kill him being handled, with a button being pushed and a black blade flicking out.
Snapchat messages between Yousef and Boy B, in September last year showed Yousef threatening Boy B because he thought he was acting like a drug dealer.
The court heard Yousef messaged him saying: "You are getting stabbed when I see you... I'm going to kill you."
Alastair Webster QC, defending boy A, said two days later Yousef sent a "conciliatory" message.
Videos recovered from Boy A's phone included one filmed three weeks before Yousef's death, showing Boy A toying with a large knife or machete and appearing to make a slashing motion across the neck of someone in the distance.
Another from 9 February showed Boy A making stabbing motions towards a hooded figure on a bed, who also makes stabbing motions with a knife as they both laugh.
Boy A has also pleaded not conspiracy to rob but has admitted a charge of perverting the course of justice and possession of a flick knife.
Boy B denies conspiracy to commit robbery and perverting the course of justice. He has pleaded guilty to possession of a flick knife.
The trial continues.