A deranged driver rammed a police car during a chase across Exeter in which he believed he was being pursued by aliens.
Officers were alerted to Brett Webber's bizarre driving after he almost knocked a motor cyclist off his machine in the centre of the city late at night.
He fled when they approached his van and then drove at slow speed until being boxed in by two police cars outside the Clifton Hill leisure centre.
He told the police he was escaping from aliens and then set off again, driving through their cordon, and driving on the wrong side of the road as he headed for the Countess Wear roundabout.
He was finally arrested in Rydon Lane but rammed a police car as it boxed him in, Exeter Crown Court was told.
Carpet cleaner Webber, aged 48, of Venny Bridge, Exeter, admitted dangerous driving and Judge Phillip Wassall adjourned his case for a psychiatric care plan to be prepared.
He was told Webber has been diagnosed with schizophrenia but a detailed plan of how he could be treated in the community is not in place.
Mr James Taghdissian, prosecuting, said an unmarked police patrol came across a motorcyclist who had narrowly avoided an accident in North Street, Exeter, at 11.30 pm on a night in January last year.
He said:"The officers recognised Webber's van and followed it as it drove around the streets of Exeter and they were joined by two marked police vehicles in Belmont Street who stopped him in Clifton Hill.
"The officers got out and spoke to Webber but he managed to drive off past them and the police were incredibly concerned because they were aware he had mental health problems and believed aliens were out to kill him.
"He drove off at slow speed through Barrack Road where police were worried that the white lines were being crossed and when he was eventually stopped he rammed the police car, causing a five inch dent to the front wing.
"This was a sustained period of bad driving leading to the ramming of the police van. When he was detained he was singing 'doh, ray, me' and said it was to ward off aliens he perceived to be threatening him."
Miss Kelly Scrivener, defending, said Webber suffers from a schizophrenic disorder and urged the judge to pass a community order which would allow his treatment.
The Judge said:"I cannot see that there is viable and workable option to punish him in the community properly for this very serious offence and his bad driving, bearing in mind this was a prolonged offence.
"I am adjourning this case to give more time to come up with a plan which will give the court a possible way of avoiding what would otherwise be an inevitable prison sentence.
"The existing proposals are too speculative and the mental health services need to put together a more coherent plan which he is more likely to stick to."
