OTTAWA -- Three years after an Ottawa man was murdered outside a Rideau Street bar, Ottawa Police are offering a $75,000 reward for information leading to an arrest of Ashton Dickson's killer.

Dickson was murdered on June 26, 2017 outside a nightclub located at 470 Rideau Street.

Police say investigators believe an altercation began in the club and continued into the street.

On Friday, Ottawa Police announced the $75,000 reward for information leading to an arrest in the case and released surveillance video from the night of the murder.

Dickson's mother Donna Dickson is thankful Ottawa Police released the surveillance video to help with the investigation.

"It was worth the push, it was worth sitting down a second time with the new chief (Chief Peter Sloly) and with the new detectives so they could get an understanding of how we felt and they want the same thing as we do, they want justice."

Donna Dickson added the reward and video "means we're getting closer to closure, we're getting closer to getting justice for Ashton."

In a statement, police say, "the shooter and his associates escaped on foot through the nearby parking lot of a motel across the street."

Security video taken the night of Dickson's death has been released, with police saying the video shows "there were multiple people who witnessed the murder and saw the killer but have not spoken to investigators. Some of these witnesses are thought to be in the Toronto area and the United States."

Investigators are urging anyone with information about the shooting to come forward.

"This is an active investigation and our detectives have pursued multiple leads over the last three years. We know that there are several people who were there and witnessed this murder but have not spoken to police," said Staff Sgt. Bruce Pirt.

"They have important information that could help solve this case. We are asking those in the video to contact us. We need your help and we need you to come forward with the information you have."

Anyone with information is asked to contact the Ottawa Police Homicide Unit at 613-236-1222, ext. 5493. Anonymous tips can be submitted by calling Crime Stoppers at 1-800-222-8477.

"This is the time to do something, do the right thing. It's been three years, I know that guilt is on your mind, is on your chest, speak the truth," said Donna Dickson.

"The longer you stay silent you are condoning what the person did that night, you are just as guilty."