Jury begins deliberations in Halifax murder trial of medical student

The jury has started deliberating in the first-degree murder trial of Halifax medical student William Sandeson.

Sandeson is charged in the death of Taylor Samson, a 22-year-old Dalhousie University student whose body has never been found.

The trial has heard Samson went to Sandeson's apartment on Aug. 15, 2015, to sell him nine kilograms of marijuana for $40,000.

Nova Scotia Supreme Court Justice Josh Arnold gave his final instructions to jury members today, and reminded them that Sandeson is presumed to be innocent unless the Crown has proved its case beyond a reasonable doubt.

Arnold told them their verdict must be unanimous, although they do not have to arrive at a conclusion in the same way.

He said if jury members are not completely sure of his guilt, they must find him not guilty.

Meanwhile, the jury retired to deliberate without hearing that the defence had sought a mistrial after a bombshell surprise.

About halfway through the trial, Sandeson's lawyers said they had just learned that a private investigator who was working for them had facilitated meetings between two key witnesses and police.

The defence argued those meetings led the witnesses to give new statements to police that further implicated Sandeson in the killing Samson.

The lawyers argued it contravened solicitor-client privilege, and was grounds for a mistrial or exclusion of the witnesses' evidence.

During many hours of hearings away from the jury, the complex issue unfolded, but it can be reported on now that the jury has been sequestered.

(With files from The Canadian Press)