A man accused of first-degree murder in the death of his mobster father-in-law testified Thursday that he pulled the trigger out of self defence.

Asked why he shot 87-year-old Rocco Zito on Jan. 29, 2016, Domenico Scopelliti told his defence lawyer, "Because I feared for my life. I feared my life was in danger. He had a gun pointed at me."

Scopelliti moved into his mother-in-law and father-in-law's house at 160 Playfair Ave. in the early 1990s, after marrying their daughter, Laura, he testified.

Scopelliti said in court that he and his wife lived there rent-free for more than two decades, but took care of the aging in-laws in recent years.

He saw Zito as a father figure, he said, adding that Zito was a pallbearer at Scopelliti's father's funeral when Scopelliti was a teenager.

According to an agreed statement of fact from the Crown and defence, Zito was thought by law enforcement to be "a figure of significant power and authority within organized crime, specifically the Italian Mafia" throughout his adult life and until his death.

Police found several guns and rounds of ammunition in the home — both upstairs where Zito and his wife lived and downstairs where Scopelliti lived with his wife and four kids.

Scopelliti told court Thursday he had been making silencers in the basement in the months before the shooting, describing the work almost like a hobby. He said he started making the silencers on Zito's advice as a way to make money and that the two of them would test the silencers out by firing guns in the basement and into the backyard.

Scopelliti described an incident in 2011 in which he said he, for the first time, disagreed with Zito about a business venture.

"You couldn't say no to him," he had testified earlier. Not without disrespecting him.

Scopelliti said Zito threw a glass at his head and came at him with a knife, but the relationship was later repaired.

The jury has heard that police found $150,000 cash in Zito's bedroom after he was killed.

Scopelliti told court that Zito made his money as a loan shark, charging 10-per-cent interest and using his reputation — which included him killing a man in the 1980s over an unpaid debt — to make sure debts were paid.

In the days leading up to the shooting, Scopelliti said Zito informed him that he wouldn't be inheriting as much money as he expected — money Scopelliti said was meant to pay for his four children's educations.

He said he called Zito an Italian word equivalent to "rat" or "snitch," the highest form of insult, according to Scopelliti, in the Playfair Ave. home.

Defence lawyer Brian Ross is expected to ask Scopelliti about the particulars of what happened the day of the shooting when the trial continues Friday.

According to the Crown, Zito was shot dead after rising from his afternoon nap. He was shot from below as he stood at the top of the stairs to the basement, the Crown said.

The Crown's theory is that Scopelliti killed Zito over frustration and anger that had been mounting for days and boiled over in the midst of an argument.