As the phasor. measurement units (PMUs) start populating the substations, their benefits for different power system application functions are being debated. One of these functions is the bad data processing that is commonly integrated into the state estimation. Bad data detection is closely related to the measurement redundancy in that bad data appearing in critical measurements cannot be detected. Such measurements, however, can be transformed into redundant measurements by adding few PMUs at strategic,locations. In this paper, it will be shown that with few extra PMUs, the bad data detection and identification capability of a given system can be drastically improved. Description of the placement Algorithm is given, and case studies carried out on different size test systems are presented.