A Saskatoon criminal defence lawyer says manslaughter charges stemming from tainted drug deaths could change how fentanyl overdoses are treated in the legal system, but doesn't foresee changes in the number of drug-related crimes.

"Merely trafficking in illicit substances isn't necessarily going to lead to a conclusion that somebody overdosing and dying is going to lead to a manslaughter charge," lawyer Kevin Hill told CBC's Saskatoon Morning.

His comments come after three men, who police allege are drug dealers, were charged with manslaughter and criminal negligence in connection with four deaths in Saskatoon last year that police connect with fentanyl-tainted cocaine.

Brian Washburn, the father of one of the victims, said last week that getting drugs beyond what was agreed upon in a sale should lead to punishment for the seller — particularly with fentanyl since "everybody knows that fentanyl kills people."

Hill agrees that there is higher risk when fentanyl is involved and that's likely what the prosecution's theory hinges on.

However, Hill said he doesn't expect drug selling or buying to change as a result of these new charges.

"The act of selling and using illicit drugs is inherently dangerous. I think all parties that are a part of that process understand that and are undertaking those actions in the face of those risks. This kind of punishment model isn't going to change those choices," he said.

Police previously told media that the men charged with manslaughter continued to sell the lethal powder even after users contacted them to say it was tainted.

It's the first time in Saskatchewan that alleged drug traffickers have been charged in connection with the death of a user. Hill said this means there are a lot of issues that need to be addressed.

"There has to be an act that is a contributing factor to somebody's death. So you have to define what the act is. Is it the trafficking of fentanyl?" Hill said.

Other questions he brought up include:

Did the dealers know they were trafficking fentanyl?

When was fentanyl added to the drugs that were sold?

Did the people committing the act know fentanyl was present?

Who would be the one considered to have committed the act of manslaughter, the people who added it or the people that sold it?

'There are things that are awful but are lawful'

Washburn, the father of one of the victims, told CBC he would like to see the manslaughter charges upgraded to murder, but Hill said it's up to the court to decide what legal obligations the alleged drug dealers held if they were aware that the drug were tainted.

"I often say that there are things that are awful but are lawful. So I think there is a separation between moral culpability and legal culpability," Hill said.

"Is there a duty to provide a safe product when you are drug dealing?"

That's a question that will play out in the courts.

The three men charged, Shervin Beeharry, Japmanjot Grewal and Azim Kabani are scheduled to return to court this week.