Four days before Tony Robles, 66, was due in a Hamilton courtroom to face charges including domestic assault and child pornography, he was found dead behind an auto repair shop. His son has been charged with murder.

Robles last moments were captured Thursday evening by a security camera pointing at the van in which he lived.

Jonathan Robles, 35, has been charged with first-degree murder in the killing, the city's seventh homicide this year.

Security camera footage from a nearby business shows a man being attacked in a parking lot behind an auto repair shop.

For nearly four minutes the video shows a man sitting on another man's chest after attacking the victim from behind. The victim squirmed and kicked his legs.

Hamilton police say a 66-year-old man was found "obviously deceased" around 7 p.m. in the back parking lot shared by a catering business and auto-repair shop.

Police announced Friday evening that a post-mortem examination revealed the victim was stabbed to death. According to a police news release, the younger Robles called 911 and then surrendered to police.

Victim a former chemist, high-earner

​Gino Piedimonte, who runs the auto repair shop near where the body was found, said he knew the victim and that his name was Tony Robles, but also went by Antonio, and that he was a former customer at Piedimonte's auto repair shop.

Here, the two men are speaking at the trunk of the car. The camper van is lit near the top of the image. The man on the left walks around the man on the right, and back toward the camper. The man on the right takes something from the trunk and then attacks from behind. (Parkdale Spring & Suspension security video)

Piedimonte said the man had fallen on hard times, was going through a divorce, and had been living out of a camper van since the previous winter. Piedimonte offered the victim a place to park his van, access to electricity, water and a washroom in the back lot where his body was discovered.

Robles once had a successful career as a chemist and was on Ontario's so-called Sunshine List as a City of Hamilton superintendent at the Burlington Street water treatment plant, earning $112,497 in 2010.

He does not appear on the 2011 Sunshine List, but may have shifted his focus to his own business, TR Research. In 2011, he and his wife, Emy Robles, were finalists in the Lion's Lair competition — Hamilton's Dragon's Den business accelerator competition — working on a water treatment process the pair wanted to sell to municipalities.

Reached by phone Saturday, Emy Robles asked for privacy and said she did not want to talk about the situation.

"I am overwhelmed by everything that happened," she said.

Court documents show that Tony Robles was due to stand trial on Monday for domestic assault, possession of child pornography, uttering death threats and possession of a firearm, a Winchester rifle, without a licence. The charges relate to a May 2012 arrest.

Fatal struggle captured on video

Security camera footage from a neighbouring business, viewed by CBC News, showed a man pulling up his vehicle behind the camper van where Robles lived.

After the man exited, he approached the camper van. The video shows two men talking for about three minutes, a conversation that became animated at times, but not violent.

One of the men then opened the trunk of a car, grabbed an object from the trunk, snuck up behind the other man and hit him in the back of the head, knocking him to the ground.

The man sat on the victim's chest for nearly four minutes as the victim's legs and arms flailed. After that the man on top got up, stood over a motionless body, and leaned on the camper van for another two minutes before walking out of view. A few minutes later two people with flashlights discover the body. A few minutes after that, firefighters enter the scene.

On Friday morning, evidence markers were all that remained. The camper van's doors were still open, and a red vehicle still had its trunk open, taped off by police.

The man on top sits on the person below. In the video, legs and arms can be seen flailing for nearly four minutes. (Parkdale Spring & Suspension security video)

Piedimonte said Robles "was very quiet, he kept to himself." They exchanged hellos and goodbyes in the mornings and evenings, and he knew Robles had split up with his wife.

Gurmel Jhuty, who runs a nearby business with a security camera that captured the incident, said the victim was due to appear in court soon. Piedimonte added that the victim was retired, and had once worked at the water treatment plant off Burlington Street.

In the 2011 Lion's Lair competition, Robles and his wife were a team working to market a water treatment process Tony Robles holds a patent for. A profile of Robles on the Mapua Institute of Technology website in the Philippines, said Robles immigrated to Canada in 1974 "full of hope." It adds his chemical engineering degree was not at first recognized, and he started out in the mining industry as a janitor before quickly climbing the ranks as a chemist.

Jonathan Robles is due back in court on Nov. 21. He does not have any prior charges, according to the courthouse which has records dating back to 1997.

jeff.green@cbc.ca