Halifax Regional Police believe a 22-year-old university student, who they say was murdered, was involved in a drug deal before his death, according to court documents.

Taylor Samson, a physics student at Dalhousie University, was last seen on Saturday after he left home in the city's south end around 10:30 p.m.

William Michael Sandeson, a 22-year-old fellow Dalhousie University student, is charged with first-degree murder in Samson's death.

According to a warrant filed in Halifax provincial court, police had "reasonable grounds" to believe there was marijuana in Samson's apartment on South Street, which he was in the process of moving into.

Taylor Samson

22-year-old Taylor Samson was reported missing on Aug. 16. (Halifax Regional Police)

Samson was reported missing by his stepmother, Karen Burke. Police then spoke to Samson's mother, Linda Boutlier, who said it was unusual for her son not to check in and let people know where he was. Boutlier also told police she was aware that her son sold marijuana for extra cash while he was in school, according to the documents.

After phoning one of Samson's friends, Boutlier said she was told her son was supposed to meet with a new "client" the night he disappeared.

Samson's girlfriend told police he left the apartment the night he disappeared with a black duffel bag, containing what she believed was marijuana.

She told police when he left, he only took his phone, leaving behind his wallet and keys, as well as medication for a liver disorder, saying he would "only be gone for 15 minutes," according to court documents. 

Victim of a 'drug rip'

Samson's friend — the same one who told his mother he left to meet a new client — told police Samson was nervous about going to meet the client and tried to get someone to go with him to the alleged drug deal. But, no one was available. 

"Samson seemed nervous about it since it was four pounds, a larger amount of marijuana than usual," according to court documents.

The documents also say that police believed Samson was the victim of a "drug rip."

William Michael Sandeson

William Michael Sandeson is charged with first-degree murder in the death of Taylor Samson. (LinkedIn)

"I have been advised by … confidential sources that 'drug rips' and cash robberies take place often; rarely reported to police," said Det. Const. Jen Lake in the warrant filed to obtain a search warrant.

"With Samson meeting a new 'client' close to his residence and not returning when expected, the investigation [has] developed to believe that Samson was the victim of a 'drug rip' and those who did so have taken him to obtain more money or information he may have related to the drug trade, his supplier and further location where drugs being held."

None of the statements in the documents has been tested in court.

Samson's body not found

Sandeson was arrested outside a home on Leaman Drive in Dartmouth on Tuesday at around 8:30 p.m.

Further investigation led police to search a home in the 1200 block of Henry Street in Halifax. Court documents list Sandeson's address as 1210 Henry St. and police say they believe that's where Samson was murdered.

The court documents do not say how police linked Samson's disappearance to the suspected murder scene on Henry Street.

Samson's body has not been found. 

Sandeson had just been accepted into Dalhousie University's faculty of medicine and was set to start as a first-year medical school student on Monday.

According to Sandeson's LinkedIn profile, he worked as a patient attendant at the Queen Elizabeth II Health Science Centre in Halifax. The Truro native was also a runner who represented Nova Scotia at the 2013 Canada Games in Sherbrooke, Que.

Police say the two men knew each other and do not believe the homicide is a random act.

Dalhousie University said both students lived off campus.