Not necessarily. It is a double-edged sword. Esp. in countries/areas with officially-sponsored highly charged religious atmospheres, and when the crime/allegation is related to the religion of the majority. It has proven to be a positive incentive to murder as well, i.e. Murder by lynch mobs. And many times the victims were/are innocent.
Also, the argument that "death penalty for blasphemers in PPC acts as a deterrent against blasphemy" can not be accepted as the statistical data proves otherwise. Between 1947 to 1979, before the enactment of 295-C, not a single case of defilement of the Holy Qur'an or blasphemy against Rasul Allah by any Muslim or Non Muslim was filed under the then-prevailing blasphemy law (which didn't carry a death penalty for blasphemy). But ever since the enactment of 295-C, hundreds of such cases have been "filed" in Pakistan, almost half of them against those belonging to religious minorities, despite the fact that minorities hardly constitute 3% of Pakistan's total population.