Gerneral Copyright Rule:

Possession vs. rights. The right to use images cannot be transferred by anyone without the written consent of the copyright holder. If you've received photographs without written permission for use, it is your responsibility to secure licensing rights before using them.

As a rule of thumb, a good way to avoid any misunderstandings is to contact the photographer before passing along photographs. You should also advise the party receiving the images to contact the photographer directly to secure a license granting permission for their use. Any copying, distribution, public display or creation of derivative works of images without specific permission from the photographer is a violation of Federal copyright law.

Simply having physical possession of photographs, slides, prints, transparencies or digital files does not grant the right to use them.

A license is a legal agreement granting permission to exercise specified rights to a work.

A copyright is a collection of exclusive rights initially owned by the creator of an original work (an image, text, song, design, etc.)

Source: American Society of Media Photographers