Police say that gang-related shootings like the one that left Ranjit Cheema dead in Vancouver this week are tough to solve because witnesses often refuse to provide evidence.

The Vancouver Police Department have confirmed that 44-year-old gangster Cheema was the victim in a Wednesday morning shooting outside his parents' home in the southeast part of the city. Investigators suspect the assassins had been surveying the neighbourhood and are asking nearby residents for help tracking them down.

"Did you see anything unusual? Did you see a car waiting on the curb for an extraordinary amount of time? Anything that comes to mind, we want to know about it," Const. Jana McGuinness told reporters.

But Chief Jim Chu said that gang shootings like this are usually hard cases to crack.

"Quite often the witnesses that we have, they don't want to cooperate. We've had witnesses in the hospital that won't give us any description of their assailants. Also, the suspects in one case may be the victims in a follow-up retaliatory attack," he said.

Investigators have little evidence to go on in the search for Cheema's killer: no footprints, no vehicle description and just a few bullet casings. Security cameras posted on every corner of the Cheema family home may offer police their best hope.

Cheema had just been released from a U.S. prison after serving time for his role in a drug-trafficking ring.

Vancouver-Fraserview MLA Kash Heed told reporters he met the dead man years ago, when the politician was working as a VPD constable.

"He was a street thug that was hyped up on enhanced steroids -- very aggressive, very assertive. It was around the time of the Bindy Johal-Ronny Dosanjh dispute," Heed said.

Both of those notorious gangsters are dead, but Cheema seemed to defy the odds before now, surviving numerous attempts on his life.

"At that time, my prediction was that he would live a very, very short life, so I'm actually surprised he lived [44] years," Heed said.

Cheema's family had no comment about his murder Thursday.

With a report from CTV British Columbia's Lisa Rossington