The young age of a Dorval teenager who fatally shot his brother is proving to be a tough challenge for both the prosecution and the defence, who have to decide on his punishment.

The teenager, who was only 12 at the time of the shooting inside their family home, finds out next month whether he'll spend time in jail.

The prosecution argued Wednesday the boy is still a danger to society, even at age 13, because he has yet to take responsibility for his actions. 

The prosecution says that to this day, it’s impossible to know how the boy obtained the gun used to shoot his brother, and even tried to blame the killing on a friend.

“In the past hearings or previous hearings, and in the meetings with those experts, he still blames everybody else or the people he frequented at the time for his behavior,” said prosecutor Marie-Claude Bourassa.

The boy cannot be named because of his age, but at the time of his brother’s death, he had already been implicated in an armed robbery, he was a drug user, and knew how to fire the gun used to shoot his brother. 

The prosecution says the boy, who's about to turn 14, should not be trusted to the care of his family or relatives, and should be sentenced to 12 months in what is called ‘open custody,’ plus six months of additional supervision after his release.

“It's not locked up, but yes, he is in a youth centre for 12 months. There are arrangements that can be made by which they can go to regular school,” said Bourassa.

The defence has a vastly different reading, and it also sees the sentencing as vastly different too. It suggests the boy should not spend any more time behind bars.

Defence lawyer Isabel Shurman argued the boy already served a full year in youth detention despite his young age. 

He is now living with relatives. 

Keeping him behind bars would simply compromise his chances at rehabilitation as he now struggles to rebuild his life, said Shurman.

His sentence will be handed down on April 25.