DALLAS (CBSDFW.COM) – A pair of robbers in Deep Ellum have found an unusual way to subdue their victims.

Dallas Police confirm three times in the past week, two men have robbed people on the street after offering them synthetic marijuana, causing the victims to pass out.

At least two of the three victims didn’t know what had happened to them until police on foot patrol woke them up on the street after they passed out.

This started last Thursday when two men approached someone on Elm Street during the overnight hours and offered a drag of what they claimed was marijuana.

It was actually what’s known as K2 or Spice, a synthetic form of cannabis that can cause people to lose consciousness.

The victim woke up to find property missing.

The same two men are believed to have done the same thing to two other people during the early morning hours on Sunday.

People who live and work in Deep Ellum are keeping their guard up but believe tourists and infrequent visitors to the entertainment district are more likely to be victimized.

“It sucks,” said Miranda Evans, who works in Deep Ellum. “It’s just tricking people and then making them helpless. I think the people that are local know better so it’s really targeting that aren’t in the area that often.”

The crime has rocked Deep Ellum which has seen recent incidents of vandalism and assaults captured on video.

Jose Sanchez has been a manager at Maracas Restaurant there for 20 years.

He says the city is becoming too tolerant of recent crime in Deep Ellum.

“It happened in 2005, the same kind of thing happened for a little bit, but it kind of kind of disappeared, so now it’s coming back again now that we’re bringing more people to the Deep Ellum area,” said Sanchez. “We need more police walking police or even bicycle security. It will help a lot I think.”

There is a photo posted by a community watch group claiming to show the suspects but police have not confirmed that to be true.