The trial of Anders Behring Breivik will wrap up on Friday with the defence expected to ask for the acquittal of the man who killed 77 people in Norway last July, but with no illusions that it will succeed.
At the end of a 10-week trial packed with gripping testimony, Breivik's main lawyer Geir Lippestad will set out his closing arguments at 9am (0700 GMT) in courtroom 250 at the Oslo district court.
Lippestad has admitted to media that he thinks his client's chances of acquittal are non-existent.
But he must formally make the request since Breivik has pleaded not guilty, despite having confessed to carrying out the murderous twin attacks on 22 July.
That day, Breivik first set off a car bomb outside government buildings in Oslo, killing eight people, before travelling to Utoeya island, northwest of the capital. There, he spent more than an hour methodically shooting and killing another 69 people, mostly teenagers.
The victims, the youngest of whom had just celebrated her 14th birthday, had been attending a summer camp hosted by the governing Labour Party's youth organisation.
With no illusion of getting his client off, Lippestad is expected to use most of his closing argument Friday trying to prove that the 33-year-old right-wing extremist is criminally sane.
With no doubt that he carried out the attacks, Breivik's trial, which began on 16 April, has focused on the question of whether or not he is sane. The answer to that question will determine if he goes to prison or a closed psychiatric ward.
Psychiatric evaluations of Breivik's mental health have sharply contradicted each other, with two court-appointed expert teams reaching diametrically opposed conclusions.
Breivik himself is intent on proving his sanity even though it will mean a lengthy prison term. He wants to establish that his far-right, Islamophobic ideology is not just the rantings of a lunatic.
Court-ordered psychiatric confinement would be "a fate worse than death," he has said. Last month vowed to the court that he would not appeal a certain guilty verdict if he was found to sane and sentenced to prison.
On Thursday, however, the prosecution called on the five judges to send him to a closed psychiatric ward, arguing his sanity had not been proven beyond a reasonable doubt.
"Our request is that he be obliged to undergo psychiatric treatment" in a closed unit, prosecutor Svein Holden said, wrapping up the prosecution's three-hour closing arguments.
It would worse to sentence someone who was psychotic to prison than to send someone who was not psychotic to psychiatric care, he said.
"We are not convinced or sure that Breivik is criminally insane, but we are in doubt," Holden said.
If however the judges chose to find Breivik criminally sane, they should sentence him to Norway's harshest penalty: 21 years in prison, with the possibility of extending the sentence for as long as he is considered a danger to society.
In defiance of Holden, Breivik stood up and touched a clenched right fist to his chest before stretching his arm out in a nationalist salute he had made on the first days of his trial in April. He had until Thursday stopped doing at the request of his lawyers.
The judges will rule on the question of whether Breivik is criminally sane or not when they hand down their verdict, which is expected on either 20 July or 24 August.