Q: Some downloaded photos have disappeared.

I got a new Macbook Pro with El Capitain installed in late July 2016.

Some of my photos have disappeared that were downloaded a short time prior to that date.

I saw them in my library, and I did not delete any of them.

Could the install have caused them to disappear?

I have gone online and have found no help.

I think the only photos that have disappeared were taken in July

prior to buying the Mac.

I saved the photos to an external hard drive, but they're not there either

which is puzzling. Thanks.

Worried