Noticing child abuse

There are so many types of abuse out there but how can you notice them. Not only as another parent, care taker, teacher, but a stranger as well. For instance, how can you tell the difference from a child acting up in public vs. a guardian who secretly hurt a child behind closed doors or in public? Children are not always easy to handle but it is hard to differ. From a strangers position of seeing a mother or father grabbing their child off the floor thinking that they threw their child across the floor vs. the mother/father picking their child up after their child threw themselves across the floor. It is hard to differ and figure it out and with laws of evidence it does not look good. "Seeing is believing".

• How can you see if a child is being abused?
• Is it just a since, physical features?
• Differing an abusive child from a child who is just throwing a tantrum?

Research:
Child abuse survivors
http://works.bepress.com/sandra_thomas/15/

Defiant Children
A book and is on word.

Behavior problems  of an autistic child
http://www.sciencedirect.com/science/article/pii/0005796763900457

Suppressing tantrum behavior in public places through the use of delayed punishment mediated by audio recordings
http://www.sciencedirect.com/science/article/pii/S0005789485800447

Stranger Intervention into Child Punishment in Public Places
http://www.jstor.org/stable/800531

Parental judgments of behavior therapy efficacy with autistic children: A social validation
http://link.springer.com/article/10.1007/BF01531563#page-1

Income and child development
http://www.sciencedirect.com/science/article/pii/S0190740909001108

Family Influences
http://www.sciencedirect.com/science/article/pii/B978012370877900061X

Parenting and family stress as mediators of the long-term effects  of child abuse
http://www.sciencedirect.com/science/article/pii/0145213494900299

The relation of childhood abuse and early  parenting experiences to current marital quality in a nonclinical sample
http://www.sciencedirect.com/science/article/pii/0145213496000920

Parenting stress and anger expression as predictors of child abuse potential
http://www.sciencedirect.com/science/article/pii/S0145213496001779

It is really hard to differ besides the oblivious because children are not always obedient. So it is very hard to tell the difference.