Richard Martin, 19, of Heath Way, Horsham, has denied murdering popular Forest School pupil Ricky, 15.

He also denies wounding with intent to cause grievous bodily harm to another teenager, who cannot be named for legal reasons.

The anonymous teenager told the jury at Lewes Crown Court that Martin delivered the first blow with a 'sideways' movement, connecting it with the side of Ricky's head.

Jury members were shown a video of a police interview with another witness, who also cannot be named.

She described the first witness trying to get the defendant, who she only knew as Richard, away from Ricky.

"Richard was holding him down with one hand and hitting him," she said.

She added: "Richard pinned him down by his shoulder.

"He just went absolutely mad, hitting both of them like he didn't care which one he was hitting."

She shouted at Martin, saying she was going to call the police.

He stopped and began to walk away, she said, but then turned and swore at her before saying: "I'll shoot you - I know who you are."

Earlier, the court had heard that Ricky swore at Martin as he was leaving the party.

A few minutes later, he returned armed with the nunchuk.

The case continues.

Regular trial updates will appear on County Times website www.wscountytimes.co.uk