HALIFAX - A Dalhousie University medical student who allegedly told a psychiatrist that he would kill up to 20 people and himself is facing an additional charge.

Halifax Regional Police say 30-year-old Stephen Gregory Tynes has been charged with unauthorized possession of a prohibited device in relation to an overcapacity cartridge magazine.

He is scheduled to appear in Halifax provincial court on Sept. 15.

Tynes was released on bail last month after he was charged with two counts of uttering threats to cause death or bodily harm and one count of engaging in threatening conduct directed at a person or any member of their family.

Search warrant documents filed with the court allege that Tynes met with psychiatrist Dr. Terry Chisholm and told her he would stab Evelyn Sutton, Dalhousie's associate dean of undergraduate medical education, and her daughter Ellen MacDonald, who was also his classmate.

The court documents allege he told the psychiatrist he had "thoughts of" shooting up to 20 people and then himself.