The murder-suicide occurred above their business enterprise, Guardian and Auto Bazaar, Garnett Street and Delph Avenue about 3 AM.
Dead are Moses and Nadia Looknauth.
Sources said that the man was highly indebted to a local commercial bank and the business was not making money.
His wife, according to sources, had also made several attempts to move out and rent a dwelling but she was unsuccessful.
Family members said the incident occurred at a time that their divorce was being finalized.
The security guard said when he assumed duty Friday night, the owner for the first time gave him the keys by letting it down in a bucket with a rope through a window. The man instructed the guard to give his son the keys when he would have arrived Saturday morning.
On entering, the son discovered the bodies of his parents on the bed. He apparently shot his wife and placed her on the bed where he hugged her and shot himself dead.
Family members said Nadia had recently accompanied a nephew to Trinidad for brain surgery, but when she arrived there her husband demanded that she return because he wanted to discuss something with her.