In order to be legally valid, an affidavit
must be signed and sworn to in the
presence of a person authorized by law to
administer oaths and to witness the
swearing of affidavits such as a Notary
Public, Commissioner of Oaths, Justice of
the Peace, County Clerk, lawyer etc.
If you cannot or do not want to do it under oath (e.g. taking an oath is
against a person’s religious or other principles) you still have to sign
your affidavit in front of an authorized person. The only difference
being that the wording of the attestation will change e.g. “Declaration
under penalty of perjury”, rather than “Thus signed and sworn before
me”.
