Yes. Under the Freedom of Information Act, anyone can request US government documents (such as FBI files) and the relevant agency will send you the unclassified parts.

For any case or only for cases that were closed? And they don't even remove SSN, addresses and phone numbers?

You can request a file on any deceased person, and they'll give it to you in most cases.

Social security numbers of the deceased are also public information. Helps to prevent identity theft issues.

You can request any deceased individual's SSN application (which includes SSN, address, birth date, parents' names) directly from the SSA with proof of death: https://secure.ssa.gov/apps9/eFOIA-FEWeb/internet/main.jsp