Search warrants are always required at a crime scene.

a. True

b. False

That statement is false.

One example would be Police actually do not need a search warrant if the search is being done in the process of making an arrest.

Another one would be if they hear a gun shot or a scream, they could enter your property without a search warrant.

This is a false statement. If the items that the authorities are looking for are in "plain sight," that is, they do not require any effort to retrieve and the items have been left out in view of everyone present, then having a warrant to retrieve them is not required.