Indeed, he argues, the same Turing's death may possibly have been an accident.
What is known and accepted is that Alan Turing died of cyanide poisoning.
His housekeeper found the famous mathematician 41 years died in his bed, with a half-eaten apple on the table beside her bed.
It is widely said that Turing had been haunted by the story of the poisoned apple in Snow White fairy tale and the Seven Dwarfs, and has resorted to desperate measures to end the same time he suffered persecution as a result of his homosexuality.
But according to Prof Copeland, Turing's habit to pick apples at bedtime, and that it is quite unusual for him to not finish it; half-eaten remains were found near his body could not be seen as an indication of a deliberate act.
Indeed, the police never tested for the presence of cyanide apples.
In addition, Prof Copeland stresses, a coroner today will require evidence of pre-meditation before announcing the verdict of suicide, but not in the account of the last days of Turing suggested him for nothing but a cheerful mood.
However, on examination, the coroner, Mr. JAK Ferns stated: "the type of people, people never know what his mental processes to do next." What is meant by "his type" is not clear.
Suicide motif is easy to imagine. In 1952, after he reported the theft of small, Turing found himself being investigated for "acts of gross indecency" after he revealed he has had a male lover in his house.
Faced with the prospect of prison, and perhaps with it the loss he held the post of mathematics at the University of Manchester, who gave him access to one of the world's only computer, Turing accepted alternative to "chemical castration" - a hormone treatment that was supposed to suppress the sex drive.
It is often repeated that the chemicals caused him to grow breasts, though Turing is known to have mentioned it only once.
Interests of the authorities continue in Turing became apparent in 1953 when a gay acquaintance of Norway, Kjell, who announced his intention to visit the postcard in her Wilmslow home, but mysteriously never arrived.
Turing told a friend, by way of explanation: "At one stage, during the northern British police are out looking for him."
With six decades back, this attention to oppress, the nation's failure to appreciate the contribution of the war, in fact marginalize the computer department in Manchester, has led to a tragic picture of Turing was hounded during his final years, and suicide becomes the natural outcome.
But Prof Copeland argues that on the contrary, Turing's career is at a high intellectual, and that he has borne its treatment "with good humor."
Of affairs Kjell, Turing has written that "the mere incident, it rivaled Arnold [gross-indecency] story", and soon after his conviction has told friends: "On the day the trial was by no means unpleasant.
"While in prison with other criminals, I have a very nice sense of irresponsibility, not like back in school."
In the face of it, this is not the expression of one's land down the difficulty.
A centennial celebration at Cambridge University considers the legacy of Turing
Moreover, Turing has been tolerated for a year of hormone treatment and conditions of his probation ("my great virtues shine") with amused fortitude, and another year has passed since apparently without incident.
In a statement to the coroner, the friends of good humor has been demonstrated in the days before his death.
Neighbors described him throwing "as merrily [tea] party" for her and her son four days before he died.
His close friend Robin Gandy, who lived with him last weekend, said that Turing "seems, if anything, more happy than usual".
But the coroner recorded a suicide verdict, "while the balance of mind disturbed".
Prof Copeland believes an alternative explanation was made at that time by Turing's mother is equally likely.
Turing had cyanide in his home for the chemical experiments he did in his spare toilet - living nightmare he calls it.
Replica Bombe Bombe decryption machine machine: We have to focus on the genius of Turing, said Prof Copeland
He has electrolysing solutions of toxins, and spoons with gold electroplating, a process that requires potassium cyanide. Although best known for his brain power, Turing also always shows the experimental bent, and this activity is not unusual for him.
But Turing is sloppy, argues Prof Copeland.
Electrolysis experiments cable to the ceiling light socket.
On another occasion, a trial has resulted in a severe electric shock.
And he was known for tasting chemicals to identify them.
Maybe he accidentally put an apple into a pool of cyanide.
Or perhaps, more likely, he did not deliberately inhale vapor from boiling liquid cyanide.
Prof Copeland noted that the nightmare room has a "strong odor" of cyanide after Turing's death; inhalation that leads to death more slowly than consumption, and that the distribution of toxins in the organs of Turing is more consistent with inhalation compared with consumption.
In the authoritative biography, Andrew Hodges suggests that the study was a ruse to disguise suicide, apparently Turing scenario mentioned to a friend in the past.
Turing Stilboestrol injected with Stilboestrol tablet - a form of estrogen synthesized
But Jack Copeland argues that the evidence should be taken at face value - that accidental death is certainly consistent with all the circumstances known at this time.
The problem, he complains, is that the investigations carried out so bad that even murder can not be ruled out. An "open verdict", recognizes this degree of ignorance, would be his preferred position.
All these reasons Turing treatment during his last years, said Prof Copeland.
"Turing hunted," he told the BBC, adding: ". But he remained upbeat and funny"
"The problem is to tell the truth as far as we know, and not speculate.
"On the one hand we are in modern times have created a narrative of the life of Turing, and we have been recreated as a happy young man who committed suicide but the evidence is not there ..
"Things are definitely Turing's death will probably always be clear," concludes Prof Copeland.
"Maybe we should just shrug us, and focus on Turing's life and extraordinary work."
Roland Pease has produced two episodes of Discovery on the BBC World Service which is intended to Turing. In the first, he followed the events that led Turing to design fully programmable computer (Ace) at the National Physical Laboratory. In the second episode, he explores the life and legacy of Turing.