Animals are unpredictable, and I believe there has to be a compelling reason to use them against a human being.
A 12-year old burglary suspect is simply not enough of a threat to sick a ferocious animal on.
And when animals do go out of control, the organization who is using them should be held responsible.
That's a different story.
Animals are unpredictable
Not nearly as bad or as dangerous as humans.
BTW, a 12 year old male silhouette in the dark can appear as a possible adult. If under similar circumstances if the suspect had been in a dark alley breaking into a bank at night, instead of a school, would you feel the same way?