Canadian authorities said Tuesday at least 22 people were murdered over the weekend when a gunman wearing a police uniform went on a 12-hour rampage across Nova Scotia. Gabriel Wortman, 51, killed “22 victims, including a 17-year-old” across 55 miles before dying in a Sunday night shootout with police, the Royal Canadian Mounted Police said Tuesday. The slayings, which Wortman carried out in a police uniform and with two decommissioned RCMP cruisers, occurred at over a dozen crime scenes, including several burned homes.

The Royal Canadian Mounted Police said they have recovered remains from some of the locations of the fires but believe the death toll may continue to rise. While Wortman’s motive remains under investigation, the RCMP said Tuesday that “some of the victims were known to Gabriel Wortman and were targeted while others were not known to the suspect.” “Our thoughts are with all of the victims’ families and we are particularly mindful of families who have not yet received confirmation that their loved ones were involved,” RCMP said in a Tuesday news release. Queen Elizabeth also gave her condolences on Tuesday, stating she and her husband, Prince Philip, are “deeply saddened by the appalling events in Nova Scotia.” “We send our condolences to the families, friends, and colleagues of those who have lost their lives,” the queen said.