TORONTO — Ontario Provincial Police have updated arrest warrants for two Ottawa men wanted in the death of Christo Allison Richards, charging each with first-degree murder.Joseph Madore, 34, and Brayton Kennedy, 28, were previously sought on second-degree murder charges. Both remain at large. Investigators now believe Madore is in British Columbia and may be travelling through or camping in remote backcountry. Police believe Kennedy may be in New Brunswick.If either man is seen, OPP said, call 9-1-1 and do not approach.Lanark County OPP officers were called to Last Duel Park in Perth at about 3:15 p.m. on April 12. They found Richards, 34, of Ottawa, with life-threatening injuries. He was taken to a trauma centre and later pronounced dead. Police have said the killing appeared targeted and that they saw no sign of a threat to the public. The park has since reopened..Two other people have been charged in the investigation. In May, Michael Lewis, 46, of Perth, was charged with conspiracy to commit murder. In June, Lyna Du, 32, of Ottawa, was charged with accessory after the fact to murder. OPP and the RCMP executed a search warrant at a rural property near Terrace, B.C., and seized two firearms. Du was scheduled to appear in the Ontario Court of Justice in Perth on June 12.OPP said in July that Madore may have been in the B.C. backcountry and that Kennedy may last have been in Moncton, N.B. The updated warrants raise the murder charge and state Kennedy may be in New Brunswick.Madore has previously been described as about 6-ft., 2-ins., and 189 lb, with a medium build, hazel eyes, black hair and tattoos, and known associations in Terrace, Richmond, Abbotsford and Chilliwack. Kennedy has been described as about 5-ft. 11-ins., and 260 lb, with brown hair, blue eyes and a tattoo above his left eyebrow.The investigation is led by Lanark County OPP under the OPP Criminal Investigation Branch, with the Office of the Chief Coroner and the Ontario Forensic Pathology Service. OPP Forensic Identification Services is assisting.Anyone with information is asked to call Lanark County OPP at 1-888-310-1122.