The method and device of this invention immobilizes a person in a secure, upright restraint system in a police vehicle. It can be easily and safely applied by public safety officers including police or other law enforcement personnel and medical personnel to secure a person against undesired movement while maintaining them in an upright, sitting position which leaves the diaphragm free for natural, unrestrained breathing movement. The asphyxia-preventing restraining device comprises an ALR/ELR retractor. The ALR/ELR retractor comprises a shoulder harness having a pair of seat belt buckles, which significantly reduces the possibilities of injuries to police officers.