Government employees are above the law. They can murder whoever they feel like, including with “high-powered, military-style, assault rifles,” as long as they feel like it.
In this case they were trying to murder an innocent lady but murdered her innocent little boy instead. Then they left him there dying within feet of his bound, innocent father who was not allowed by his overlords to even hold his baby as he died.
Thin blue line, toughguy!