 Between 1985 and 1990 he was appointed as an "operational in-charge", senior operational in-charge and later chief of the section of the General Directorate for the prevention of economic crimes and crimes against public treasury of the Ministry of Internal Affairs in Moscow.A promotion follows first to the position of chief of the General Directorate for the prevention of economic crimes and crimes against public treasury of the Ministry of Internal Affairs of the Republic of Moldova (1990–1991), then to the position of chief of Economic Police Directorate of the Ministry of Internal affairs in the Republic of Moldova (1991–1992).In February 1992, Catan was appointed secretary of state with rights of Prime-viceminister of the Internal Affairs of the Republic of Moldova, and in December of the same year he is appointed prime-viceminister and chief of the Department for Public Security of the Ministry of Internal Affairs.