The director and employees shall cooperate and exchange information with any other law enforcement agency both within and without this state, including federal authorities, for the purpose of preventing and detecting crime and apprehending criminals and detecting and stopping vehicles transporting hazardous materials contrary to the rules promulgated by the commissioner of safety and pursuant to N.H. Rev. Stat. § 106-B:15. With the approval of the commissioner of safety, the director may, on the request of any responsible official of any such agency, assist such official by detailing to him such police employees, for such length of time and under such conditions as the director may deem proper. The director may designate for liaison with the offices of the respective county attorneys or sheriff such number of state police employees as he may deem advisable for each county.