Commander Chalker joined the Northern Territory Police Force in January 1994 and has performed uniform duties in Darwin and Alice Springs, and remote community policing in Groote Eylandt, Hermannsburg, Papunya and Kalkaringi. He is a designated Detective and has served in criminal investigations in Alice Springs and Darwin including major crime, drugs/intelligence and organised crime sections. As a Superintendent, he performed duties as a Territory Duty Superintendent, in the Darwin Operational Service Division, as Chief of Staff and in Major Crime.
In July 2011, he was promoted to Commander and relieved as the Commander Crime and Specialist Support Command prior to commencing in his new role as Commander Darwin Metropolitan Command on 27 September 2011.
Commander Chalker's career highlights include policing in remote aboriginal communities, and in particular, coordinating the evacuation and subsequent repatriation six weeks later of 1500 people from Kalkaringi and Daguragu due to the Victoria River floods. In 1999, he was awarded a Royal Humane Society Bronze Medal for Bravery for entering flood waters and rescuing a man who had been swept down river in Wattie Creek near Daguragu. Commander Chalker also has a number of career highlights through his homicide, serious drug and organised crime investigations including securing a murder conviction in Alice Springs and realising significant prosecutions against a well known organised crime group.
As Chair of the Police Uniform Committee, Commander Chalker oversaw the change management process to source and transition into a new frontline uniform for the Northern Territory Police Force that included a majority vote by police officers to change colour from the traditional khaki to navy blue.
More recently, he was the Event Controller for the visit to Darwin by the President of the United States of America and commanded the Emergency Operations Centre to ensure the effective deployment of the largest ever security contingent by the Northern Territory Police Force.
He has a Bachelor of Business majoring in Human Resource Management and Administrative Management, has completed the AFP Management of Serious Crime course and holds a Graduate Diploma in Applied Management courtesy of the Police Management Development Program. He also undertook a Churchill Fellowship in 2006 studying international law enforcement agency responses to outlaw motorcycle gangs.