The Bustins joined CBM in 2002 to teach at the Kalimantan Theological Seminary in Pontianak, Indonesia, where they helped to train and mentor future leaders for local churches. They moved to Rwanda in August 2012. Darrell currently serves as the theological education specialist, focused on church leadership development with all of CBM's partners in Africa. He works with pastors, as well as those studying to be pastors and church leaders. Laura Lee is responsible for overseeing the administrative details for the short-term mission (SENT) teams that come to Rwanda.

Darrell is from Moncton, New Brunswick. Laura Lee is from Pugwash, Nova Scotia. After attending CBM’s Conference on Overseas Ministries in January 2002, Darrell and Laura Lee felt that God was calling them to move into overseas ministry that both have felt since childhood.

They have two children, Bronwyn, and Caleb and his wife, Aynsley, all living and working in Moncton, NB.