Be careful not to do anything rash without notifying the attending.
Last week I saw a 6 year old with a head lac, which the kids mother said occurred at his dads house (the dad was not present in the ED; the mother brought him in). The mother's story about how he got hurt was very ambigious about what happened - seemed at first to blame another sibling then said something about wrestling and immediately seemed to divert the conversation. Anyway he had what looked like 2 well circumscribed circular lesions in the lumbar region of his back (about half the diameter of a penny - looked immediately like cigarette burns to me). Also in his prior charting notes within our EMR saw claims about his father being "aggressive" (was a note from an outpatient visit to another physician).
This was the kids 3rd trip to the ER for a head injury within 2 years.
I let the attending know about all these things. He caught a glance at the scars I saw, but after I presented to the patient and he sewed the laceration, I don't think he did anything. All he said to me was, "Good job." Really hope that kid isn't getting thrown into walls at home, but then again I guess I trust my attendings can sniff these things out better than I can, or at least I hope so.