Alberta RCMP have charged a man with first-degree murder following a lengthy investigation into the 2020 death of an 18-year-old Chestermere resident.Sahil Grewal died in the hospital on April 6, 2020, three days after he consumed a noxious substance allegedly delivered to him by Mohit Sandhu, now 23, of Conrich, Alta.In a news release, the RCMP said their Major Crime Unit has laid two charges against Sandhu, first-degree murder and attempted murder, after a five year long investigation.Mounties allege the same substance was also intended for a second person, 25-year-old Jaskaran Sidhu of Calgary. However, Sidhu did not consume the substance and was not harmed..Police did not identify the substance involved, nor did they offer details on a possible motive.Sandhu is currently in custody on unrelated matters, RCMP said. It is not yet clear when he will appear in court on the new charges.Police say no further details will be released at this time.