Why are healthcare professionals often in a good position to notice domestic abuse

Healthcare professionals are the one who provide medical treatment to the victims of domestic abuse.

Explanation:

The sufferer of domestic violence needs primarily a medical care to treat their wounds. They are the one who have the right to inform the police about the victim’s condition and they also have the right to note down the injuries of the victim to help her in winning the case against the person in court.

This documentation of injuries provided great help to the victims only if it has accuracy to prove the case.

when comparing the cases, what similarities are there in the cases that suggest one person committed these murders?