This is a really sad story out of Farmington, New Mexico that may have still occurred even if the dogs owners had been home at the time.
Police were attempting to arrest a suspect after they found $100,000 worth of methamphetamine in his house. The suspect attempted to evade arrest by jumping into the neighbor's backyard.
Unfortunately, two territorial dogs lived at the house and were housed primarily in the backyard. They attacked the suspect but apparently did not attempt to attack police who followed. Police had to make a decision and ended up shooting the dogs, killing one and wounding the other.
The person arrested and his "drug gang" sold about 10lbs of meth weekly. At the very least, the dog stopped him from escaping.