Randy Tshilumba, the 21-year-old man charged with first-degree murder in the death of Clémence Beaulieu-Patry, 20, has admitted stabbing to death the grocery-store clerk in front of horrified customers in April 2016.

Tshilumba began testifying in his own defence this morning at his trial for Beaulieu-Patry's murder at the Maxi store where she worked in the Montreal district of Saint-Michel.

Tshilumba testified he stabbed Beaulieu-Patry because he'd been terrified for months that she and her friends were trying to kill him.

In his opening statement, Tshilumba's defence lawyer Philippe Larochelle told the jury he would introduce evidence that shows Tshilumba is mentally ill and that he didn't believe he was doing anything wrong at the time of the killing.

Victim made 'indirect threats' on Facebook, Tshilumba testifies

Wearing a light blue dress shirt buttoned all the way to the top and grey dress pants, Tshilumba answered Larochelle's questions without hesitation in a monotone voice, occasionally with a slight stutter.

Tshilumba told the jury that he had gone to the same high school as Beaulieu-Patry and knew her in passing.

He said in 2014 he started to become concerned that Beaulieu-Patry and four of her female friends wanted to do him harm.

Clemence Beaulieu-Patry

Clémence Beaulieu-Patry was stabbed to death while working at a Maxi supermarket in Montreal's Saint-Michel district. (Facebook)



He said he based this on posts he saw in spotted pages of Facebook.  He said he couldn't remember the exact language of the posts, but he was convinced that Beaulieu-Patry and her friends were making what he called "indirect threats" against his life.

Tshilumba testified he began to feel increasingly anxious about this in the summer and fall of 2015.

He said he was convinced Beaulieu-Patry and her friends were spying on him. He said he lost sleep, couldn't concentrate at school and was frequently anxious and terrified.

Bought hunting knife to protect himself

In October 2015, Tshilumba was working, selling memberships for President's Choice credit cards in various grocery stores.

He said one day he was assigned to work at the Maxi store on Papineau Avenue where Beaulieu-Patry worked.  When he saw her there, he said he was anxious and scared, hiding in the lunch room before leaving the store.

Tshilumba testified that a short time after that he purchased a hunting knife for his own protection.

Tshilumba said he consulted two doctors about his anxiety, but he refused to tell them exactly why he was anxious and feared for his life.  He testified he felt that information was "private."

One of the doctors prescribed antidepressants in December 2015.  Tshilumba testified he only took one of the prescribed pills then stopped.

He said he was convinced Beaulieu-Patry and her friends were working with the doctor to prescribe him drugs that might hurt him.

'Yes, I admit it,' accused tells court

Larochelle asked Tshilumba about the night of the killing, asking him directly if he killed Beaulieu-Patry.

"Yes, I admit it," Tshilumba replied.

"Why?" Larochelle asked.

"I understood that she was going to kill other clients in the store. I panicked and killed her," Tshilumba replied.

Tshilumba testified he went to the Maxi store that night to try to convince Beaulieu-Patry to leave him alone.

He said when he confronted her, he became "very, very anxious" and was concerned that she might pull a gun.

"She was looking at the other clients, and I wanted to protect them," Tshilumba testified.

He said he then remembered stabbing her five or six times in the chest.

Tshilumba said Beaulieu-Patry fell into his arms, and then he stabbed her in the back.

Tshilumba said at that point he ran from the store and hid in a nearby Tim Hortons, saying he was still afraid that Beaulieu-Patry and her friends might try to do him harm.

Tshilumba surveillance video

Surveillance video from the Maxi grocery store where Clémence Beaulieu-Patry was killed shows Randy Tshilumba fleeing the store in the minutes after the fatal stabbing. (Screen capture from Maxi surveillance camera)



His testimony continues Thursday afternoon.

Larochelle told the jurors they'll also hear from Tshilumba's friends and family about how he changed in the months leading up to the killing.

And he said two psychiatrists will testify that Tshilumba suffers from mental illness.