Investigators are asking for the public’s help in locating a man who is a witness in a murder trial in Halifax.

Police say a Canada-wide warrant for witness was issued for Walter Madeaus Brooks on May 12 after he failed to make arrangements with police or the Crown to attend the trial at Nova Scotia Supreme Court.

Brooks is a witness in the second-degree murder trial of Demarques Shane Beals, who is accused in the death of Keya Knita Simon.

Police responded to a report of a stabbing at 117 Pinecrest Drive in Dartmouth on Jan. 8, 2011. When officers arrived, they found 19-year-old Simon unresponsive inside the front doors of an apartment building. Her 32-year-old sister had also been stabbed, but she survived.

Beals was charged in Simon’s death in August 2014. His trial began on May 15.

Police believe Brooks is living in Orangeville, Ontario, but he is originally from the Halifax area.

Anyone with information on his whereabouts is asked to contact police or Crime Stoppers.