Under immense pressure inside a Nova Scotia courtroom this February, Duncan Charles Todd Mullin pleaded guilty to possessing 6.8 kilograms of cocaine for the purpose of trafficking.

The 35-year-old Chipman, N.B., man was immediately sentenced to four years in a federal penitentiary.

But the white powder police believed was cocaine turned out not to be cocaine at all.

Tests reveal cutting agents

When Health Canada analyzed the six seized packages two months later, tests showed five samples contained Lidocaine and one contained Phenacetin. Both are prescription drugs and are not illegal under the Controlled Drugs and Substances Act.

"Both of those substances … have been used as what's called a cutting agent, which means it's a substance that criminals mix with cocaine to increase the volume and therefore increase their profits when they're selling the cocaine that they have," federal Crown prosecutor Monica McQueen said in an interview.

Mullin and his former spouse Melissa Anne Comeau were arrested in Kemptown, N.S., on Feb. 18 after the 2006 Jaguar Mullin had borrowed from the car dealership where he worked slid off the snow-covered road and into a ditch.

At the time, Colchester District RCMP alleged they found the cocaine in a gym bag in the trunk of the car. The couple was travelling to Nova Scotia to visit Mullin's ill grandmother.

Felt pressure to plead guilty

The Nova Scotia Court of Appeal threw out Mullin's conviction in May. But Mullin is still in custody at a provincial New Brunswick jail for outstanding arrest warrants for breaches, theft and forgery charges.

In a telephone interview from the jail, Mullin said when he went into court on Feb. 21, he felt pressured to plead guilty after he was told the court was not going to release Comeau, who was 8½ months pregnant, unless he did.

This is the 2006 Jaguar Duncan Mullin borrowed in February that RCMP searched for drugs in Kemptown, N.S. (Trevor Dow)

Authorities had also placed the couple's two-year-old son, who was with them in the car when they were arrested, into the care of child welfare. The child has since been returned.

"Melissa was just in the car with me for the day for the drive," Mullin said. "They were going to keep charges against her also. And she didn't even know what was going on."

Charges have lasting impact

Mullin said he was ecstatic when his lawyer told him the drugs were not cocaine. But these charges, he said, still have a lasting impact.

"It screwed everything up," he said. "I sat in federal custody for three months, PTSD, post-traumatic stress, I (had) never been a federal inmate before.

"I'd only ever done a month in jail in my life up until now."

The Crown withdrew similar charges against Comeau. She says she still cries over the ordeal, which landed her jail for about a week.

"My kid was taken from me. I wasn't allowed to come home for days … to be able to see my other boys," Comeau said in an interview. "That was very hard on them. It was hard on me."

No knowledge of drugs in car

Comeau claims she didn't even understand why she and Mullin were getting arrested.

"I've been a full-time mom for the last 6½ years. I have never jeopardized my children," she said. "I have never gotten into any types of situations like that. I've always been there for my kids.

"Next thing you know, I'm pulled off and hauled into jail."

Comeau has a criminal record for minor offences. The couple is no longer together.

Field test gave false result

Mullin told CBC News that he tried to tell officers it was not cocaine and that they would have known this if they had properly tested it.

Mullin claimed he did not even know there were drugs — outside of four grams of marijuana — in the car. And he said he did not know who owned the white powder.

A field test result led a police officer to conclude that the white powder was cocaine.

He pleaded guilty to possessing marijuana at the same time he pleaded guilty to the cocaine charge.

According to the Appeal Court documents, the bag contained six plastic bags of white powder that appeared to be cocaine. A police officer did a field test on a sample from one of the bags and the test strip turned from pink to blue. Based on that officer's experience, he believed the substance was consistent with cocaine.

McQueen said the bags were packed in a way that is consistent with the way cocaine is often found by police in investigations.

Miscarriage of justice alleged

On March 27, just over a month after Mullin pleaded guilty, his Amherst lawyer, Jim O'Neil, filed a notice of appeal. One of Mullin's grounds of appeal was that the substance seized by the police was not cocaine.

He also claimed his conviction resulted in a miscarriage of justice because the police exerted undue pressure on him to enter guilty pleas, promising to release Comeau from custody, withdraw her charges and release his child from protective services.

"At that point in time, the Crown arranged to have the substance tested, which is usually a process that takes place before trial. But, of course, Mr. Mullin didn't have a trial when he pled guilty," McQueen explained.

"On your first appearance, of course, the Crown doesn't show up with all of its witnesses and its exhibits to put before the court. And the nature of a guilty plea is very clear.

"When a person pleads guilty, they are giving up their right to have a trial and the Crown is no longer required to prove the offence."

'It is clear this man is innocent'

In the court papers, O'Neil spoke of the urgency of releasing Mullin on bail pending his appeal.

"It is clear this man is innocent and there are disturbing circumstances," O'Neil wrote in an April 26 email to the Appeal Court's registrar.

Earlier that morning, McQueen told the registrar in an email that there had been a "significant change in the circumstances of this file."

"The police received from Health Canada confirmation of the nature of the substance analyzed, and found them not to be cocaine, which was of course the essential element of the criminal liability of Mr. Mullin for the conviction which is currently under appeal," McQueen wrote.

Once the test results came back showing the substance was not cocaine, the Crown told Mullin and his lawyer that it would be consenting to his appeal to have his conviction overturned.

And on May 25, the Nova Scotia Court of Appeal set aside Mullin's guilty plea, quashed the Feb. 21 conviction and entered an acquittal. To allow the conviction to stand, the court said, would result in "a miscarriage of justice."

Truro defence lawyer Jeffrey Lattie represented Duncan Mullin the day he pleaded guilty to possessing cocaine and marijuana for the purpose of trafficking. (Jeffrey Lattie)

Truro defence lawyer Jeffrey Lattie represented Mullin as duty counsel for his first court appearance only — the day he pleaded guilty.

Lattie said the jeopardy that Mullin and Comeau faced if they were both sent to prison was a paramount consideration in Mullin's decision to plead guilty.

Mullin pleaded freely and voluntarily

Lattie is not aware of police or any other justice official placing Mullin under any type of duress to plead guilty.

"I think that the pressure Mr. Mullin was under was the fact that these are serious allegations and the quantity of substance that was seized, I think that was part of the stress, if you will," he said.

Lattie stressed that Mullin chose freely and voluntarily to plead guilty to the charges, with the understanding that he was forgoing his right to a trial and that he was admitting the elements of the offence.

The four-year sentence was a joint recommendation of the Crown and defence.

Rare and unusual case

O'Neil, the Amherst lawyer who represented Mullin for the appeal, calls Mullin's a rarity in his 30 years of practice.

"In all my years of criminal law practice, I really haven't seen anything like it," O'Neil said.

Mullin contacted O'Neil after he was sent to prison. He told O'Neil he had pleaded guilty to the drug trafficking charge but was not guilty.

"I wondered how could this be," O'Neil said. "Normally in drug cases — and I've done an awful lot of these cases — there's an analysis done by Health Canada and that analysis often takes a month, two months or longer to do the forensic analysis. In this case, that wasn't done."

O'Neil is not sure whether the Crown has launched an investigation into the case.