What does "shall-issue" mean?
What does "shall-issue" mean?
Here is what I read. Thanks in advance.

States that implemented "shall-issue" concealed carry laws reduced murders by 8.5%, rapes by 5%, aggravated assaults by 7%, and robbery by 3%.

Question

What does "shall-issue" mean?
What does "shall-issue" mean? 
Here is what I read. Thanks in advance.

States that implemented "shall-issue" concealed carry laws reduced murders by 8.5%, rapes by 5%, aggravated assaults by 7%, and robbery by 3%.

Answer

In the context provided, "shall-issue" means that if an applicant for a concealed carry permits meets the criteria for applying for that permit the state issue it.   Other states have "may-issue" laws which means the state may, but is not required to, issue permits.   "Shall" means "you must" where "may" means "you can if you want to".