Why were charges against 35 Mafia associates in Montreal stayed?

On March 21, crown attorney Sabrina Delli Fraine, explained to reporters why the Crown decided to stay charges in a major prosecution of 35 organized crime suspects in Montreal.

"There are questions, disclosure issues that have been raised concerning among other things the techniques that were used by the RCMP in the course of their investigation," she said.

All suspects were arrested in 2014, as part of a much-trumpeted RCMP operation against mafia activity.

Federal prosecutors have been somewhat vague about the reasons why the would let such high profile arrests walk free.

But it appears RCMP surveillance tactics involved in building the case play a big part.

At the time of the arrests, RCMP boasted that more than a billion BlackBerry messages had been intercepted in their investigation. And it seems there's reluctance from the RCMP to reveal exactly how they collected the information.

Security expert Christopher Parsons knows a bit about the secret technology. He explains how the use of a stingray, a mobile device indicator (MDI), can gather information without people knowing.

"What these [devices] do is they fake cell phone towers. So when your mobile phone is normally operating, you're connected to a Telus, Bell watertower. When one of these devices goes on, your cellphone will connect to it on the basis that it has a stronger signal," Parsons explains to The Current's Anna Maria Tremonti.

Parsons, who is a research associate at the Munk School's Citizen Lab, at the University of Toronto, says there's also an equipment identifier in your phone that authorities can collect and send what's called a silent text.

"So they send you a text message. You never see it because your phone will never display it but it will respond. And in doing so will provide your phone number."

The RCMP have gone to great lengths to keep details of how the device is used under wraps and Parsons suspects there are more intelligence gathering techniques that are secret.

"The full range of what exactly is being used, and what they're targeting, and how — that unfortunately I have not been able to divine just yet," he tells Tremonti.

"It's been a couple of years to figure out that they're even using it. But that's an ongoing research at the Citizen Lab."

Listen to the full segment at the top of this web post.

This segment was produced by The Current's Sam Colbert and Steph Kampf.