Sajjan joined The British Columbia Regiment (Duke of Connaught's Own) in 1989 as a trooper and was commissioned in 1991.  He eventually rose to the rank of lieutenant-colonel. He was deployed overseas four times in the course of his career: once to Bosnia and Herzegovina, and three times to Afghanistan. Sajjan was wounded during his service in Bosnia. Sajjan began his 11-year career as an officer of the Vancouver Police Department after returning from his Bosnian deployment. He ended his career with the Vancouver Police Department as a detective with the department's gang crimes unit specializing in drug trafficking and organized-crime investigation.Sajjan's first deployment to Afghanistan was shortly before the start of Operation Medusa in 2006, during which he took leave from his work in the Vancouver Police Department's gang squad. He deployed with the 1st Battalion, Royal Canadian Regiment Battle Group in Kandahar and worked as a liaison officer with the Afghan police. His fluency in Punjabi, his first language, allowed him to be understood by Urdu-speaking Afghans without translators, especially by village leaders who were invaluable to his intelligence gathering. Sajjan found that corruption in the Afghan government was driving recruitment to the Taliban. After reporting these findings to Brigadier General David Fraser, Sajjan was tasked with helping the general plan aspects of Operation Medusa.During Operation Medusa, which lasted from September 2 to 17, four Canadian soldiers under Sajjan's command were killed in the fighting. Fraser evaluated Sajjan's leadership during the operation as "nothing short of brilliant". When Sajjan returned to Vancouver, Fraser sent a letter to the police department which called Sajjan "the best single Canadian intelligence asset in theatre", stated that his work saved "a multitude of coalition lives", and noted that the Canadian Forces should "seek his advice on how to change our entire tactical intelligence training and architecture". Sajjan was mentioned in dispatches for the usefulness of his tactical counterinsurgency knowledge in the planning and implementation of an unnamed operation in September 2006 to secure important terrain.Upon his return, Sajjan left his position with the Vancouver Police, but stayed as a reservist and started his own consulting business that taught intelligence gathering techniques to Canadian and American military personnel. He also consulted for US policy analyst and Afghanistan expert Barnett Rubin, which began as a correspondence over Sajjan's views on how to tackle the Afghan opium trade and evolved into a collaboration as advisers to American military and diplomatic leaders in Afghanistan.Sajjan returned to Afghanistan for another tour of duty in 2009, taking another tour of leave from the Vancouver Police Department to do so. Having already taken two leaves of absence, Sajjan had to leave the Vancouver Police Department for his third tour of duty in 2010, during which he was assigned as a Special Assistant to then Major-General James L. Terry, the commander of American forces in Afghanistan.In 2011, he became the first Sikh to command a Canadian Army reserve regiment when he was named commander of The British Columbia Regiment (Duke of Connaught's Own).He was bestowed with the Meritorious Service Medal in 2012 for diluting the Taliban's influence in Kandahar Province. He has also been awarded the Canadian Peacekeeping Service Medal. He also received the Order of Military Merit award.  He also served as an Aide-de-Camp to the Lieutenant Governor of British Columbia.His Sikh beliefs require him to keep his facial hair which prevents the use of regular military gas masks, so Sajjan invented his own gas mask that worked with his beard, and patented it in 1996.

Question: Where did Sajjan begin his career after his service in Bosnia?
Answer: he Vancouver Police Department