How to find out which application(s) created core dumps?
The handling of coredumps has changed on Mojave, so you cannot use "otool -c" as you did on older macOS versions. Instead you open the Terminal and run the following command:

lldb -c /cores/core.12345


where 12345 needs to be replaced by the actual filename of your coredump file.

When lldb has started up, you'll get an (lldb) prompt, where you enter the following command:

target list


Then you should be shown which program crashed. For example like this:

(lldb) target list
Current targets:
* target #0: /usr/local/bin/emacs ( arch=x86_64-*-*, platform=host, state=stopped )


In this case the crashed program was "emacs" in the folder /usr/local/bin.