Hundreds of people accused of committing crimes in Calgary have walked away from their charges in the past year because there aren't enough prosecutors to run trials, CBC News has learned.

Every week, an average of one full day of low-complexity trials are stayed, but there have been weeks when prosecutors are dumping up to three days' worth of cases.

The numbers come from the Alberta Crown Attorneys' Association (ACAA).

Most recently, all cases set for Monday in Courtroom 507 were stayed by the Crown.

Low complexity cases are matters that take less than half a day for trial and can include charges of theft, assault, shoplifting and mischief, as well as breaches.

"I fully support the decisions that were made in these cases," said Eric Tolppanen, assistant deputy minister with Alberta Crown Prosecution Service, Justice and Solicitor General.

Tolppanen says the current situation is a reflection of the gap between the number of prosecutors and the number of viable charges laid by police.

"These decisions are required in order to ensure that currently available resources remain focused on serious and violent crime."

'Longstanding problem'

Alberta prosecutors have the highest caseload in the country behind Saskatchewan and more hires are desperately needed, according to the ACAA.

The assistant chief Crown for the low complexity unit will look at the schedule for Courtrooms 506 and 507 a week or two in advance.

Often, there are no prosecutors to send to court on a given day, which results in letters being sent to defence lawyers advising that charges against their clients have been dropped.

There are on average six trial days set per week for low complexity matters, which are run out of two courtrooms. Each day, three to eight trials are scheduled with an average of five taking place.

"We don't have enough prosecutors to staff all the courtrooms," said Matthew Block with the ACAA. "This is a longstanding problem."

There is a 17 to 50 per cent chance an accused person facing trial on low complexity charges will see their charges dropped.

Alberta's extreme caseload

That means as defence lawyers learn of these types of stays, they're more likely to book a trial that will increase backlog and the frequency with which charges will be dropped.

The only solution is to hire more prosecutors, says Block.

About 350 prosecutors are employed in Alberta. Calgary General Prosecutions has 66 prosecutors.

With 309 people charged per prosecutor, Alberta's ratio is the highest behind Saskatchewan.

For comparison, Ontario, Quebec and British Columbia prosecutors handle an average of 193, 175 and 121 persons charged, respectively.

50 new prosecutors promised: UCP

The province hasn't been hiring prosecutors at a rate to keep up with an increase in the number of charges, the complexity of charges and population, according to the association.

"At a certain point, things have to give, and there's all sorts of these areas that are giving, in the prosecution service overall," said Block. "This just happens to be a very noticeable one."

Generally, there are two reasons a prosecutor will stay a charge — when there is no reasonable likelihood of conviction or if there is no public interest in pursuing a prosecution. In this case, though, the charges have been screened for trial and are considered viable.

Prosecutors are already triaging their cases to alleviate backlog and ensure the most serious crimes make it to trial after a 2016 Supreme Court of Canada decision put hard deadlines on how long cases could take to be tried.

Individual prosecutors are expected to triage their own caseload, which is a separate issue when an entire day of trials is stayed.

During his election campaign, Premier Jason Kenney said he would hire 50 new prosecutors if elected, a commitment he reiterated on Tuesday after this story was originally published.

"We will provide our justice system with the tools and resources necessary — including an additional 50 prosecutors and support staff — to ensure Albertans have a fairer, faster and more responsive justice system," said Jonah Mozeson, a spokesperson for Justice Minister Doug Schweitzer.

The government could not provide more information on when those hires might happen.