HAMILTON -- An Ontario judge told jurors to disregard statements made by the key players in the trial of two men accused of killing Tim Bosma as the four-month trial nears its conclusion.

Justice Andrew Goodman began his legal instructions to the jury on Friday in the trial of Dellen Millard and Mark Smich, who have both pleaded not guilty to first-degree murder.

Goodman told jurors to disregard Smich's comment that he agreed to testify and noted his co-accused decided not to do the same.

"That comment was entirely gratuitous and self serving," Goodman said.

"That cannot be used against Millard ... such an assumption flies in the face of the presumption of innocence."

Goodman also said a portion of Crown attorney Tony Leitch's closing argument was improper when he said Bosma should not be forgotten.

"No accused can be convicted based on the emotion or sentiment on the victim or his or her family," Goodman said.

The judge spent much of the day going over the jury's responsibility and the mountain of evidence in the trial.

He said there is only one route to a first-degree murder charge in this case, which must include planning and deliberation.

Goodman said there is a sometimes an alternate route to first-degree murder through forcible confinement, but that isn't an option in this case. He didn't explain why.

Millard was initially charged with forcible confinement when he was arrested while Bosma remained missing. He then faced a first-degree murder charge after Bosma's charred remains were discovered on his farm near Waterloo, Ont.

The judge also instructed jurors that two people can be found guilty of the same crime in Canada.

"The distinction of those who personally commit a crime or those who aid or abet are all equally culpable in the eyes of the law," Goodman said.

The Crown alleges Millard and Smich meticulously planned to steal a pickup truck, kill its owner and incinerate the body.

Goodman told jurors they can also return a guilty verdict for second-degree murder or manslaughter for either accused, or a not-guilty verdict.

Goodman said there is overwhelming evidence the pair were the ones who took the Hamilton man for a test drive before his death on May 6, 2013.

But the jury, Goodman said, must decide what happened after that test drive began. Bosma vanished after taking two strangers out in the truck he was trying to sell.

The judge also told jurors they must return a unanimous decision as they prepare to begin deliberating on Monday.

"Two people are charged and you must return a separate verdict on each," Goodman told the jury. "Verdicts may be, but do not have to be, the same for each."

Goodman cautioned the jury not to use "bad character evidence" -- such as the pair's previous thefts, drug use or Smich's criminal record -- as a reason for guilt. The judge said such evidence can only be used to evaluate each man's credibility and reliability.

Smich told the jury Millard shot and killed Bosma and then burned his body.

Millard's lawyer said Smich accidentally shot Bosma after pulling a gun to try to steal the Hamilton father's truck.

The judge is to conclude his legal instructions to the jury on Monday.