Read the scenario.

The police are going door-to-door in a neighborhood to interview residents about a series of crimes in the area. As they approach one door, they hear loud noises from inside the house, including someone shouting for help. The police do not have a warrant, but they quickly enter the house to see whether someone is in danger.

Under what grounds might this search be lawful?
Miranda rights
double jeopardy
probable cause
search and seizure

Relax