A jury has heard harrowing police radio messages from the scene of the Broadwater Farm riots reporting that Pc Keith Blakelock had "stopped breathing with a knife in the back of his head".
The Old Bailey trial of Nicky Jacobs was played recordings of the communications by officers who attended the disturbances in Tottenham, north London, on October 6 1985.
Jacobs, 45, denies frenziedly stabbing the beat bobby to death when he was just 16.
The jury heard that Pc Blakelock and other officers in his unit at first had the situation "contained" as they went to assist firefighters trying to put out a blaze in one of the estate's blocks.
But after going into the building and coming under attack from a mob of over 100 rioters, confused messages calling for "urgent assistance" could be heard.
After they came under attack by a mob wielding "knives and machetes", one officer reports "we have a Pc who I think is dead, can we get an ambulance?"
When asked for an update on the policeman's injuries, Chief Superintendent Colin Couch, the most senior officer on the scene, is heard replying: "Severe head injuries, stopped breathing.
"It is very serious, the Pc situation here. Having tried to make him go back to breathing we now have a knife in the back of his head."
When asked for more details, Mr Couch replied: "Standby, we're doing resuscitation.
"I'm afraid to be rather vague but he's thought to be 718 Blakelock from Muswell Hill, but regretfully as you can imagine the numbers are a little bit confused at the moment.
"I'm relying on other officers that knew him but we do have three officers from this unit that's gone to hospital, one very seriously."
The trial was adjourned and the jury will return on Wednesday morning.