SANTA FE (AP) _ A new state law will prohibit euthanizing animals in gas chambers. Gov. Bill Richardson signed legislation into law on Monday that prohibits the use of carbon monoxide gas chambers to kill dogs and cats at animal shelters. That's done only in four communities-Clovis, Jal, Lovington and Tucumcari according to supporters of the legislation. Other animal shelters use lethal injection. The governor signed separate legislation that's intended to make it easier for New Mexico shelters to use lethal injection. The new law will permit trained euthanasia technicians, who do not have to be veterinarians, to purchase and administer the drugs used for euthansia of animals.