Yes, the French government should crack down on religious radicals. If religious radicals in France are committing crimes against others, the government should do something about this immediately before this gets out of control. The French government cannot let the presence of religious radicals grow within the country for people's safety.
Yes the French government should do as much as they can to crack down on religious radicals. Cracking down on the type of people who commit horrible acts in the name of religion is tricky, but it is inhumane and dangerous the way they behave and can not be allowed in a functioning society. If they don't crack down the problem is likely to get worse as time goes by.
The French government must crack down on on violent radicals, including religious radicals. Yes, religious liberty must be protected, but not at the costs of public safety. The French government should be able to arrest religious radicals suspected of supporting violence or terrorism. Terrorists suspects should not be able to hide behind religion for protection.
While the death of the French priest is a great tragedy the problem is not religious radicals, so much as it is the level of religious persecution in France and the limited amount of religious freedom. Until this changes France will continue to experience attacks cause by an angry and marginalized people.