The conjugation 護らねば and the use of 謙譲語 for suspects/criminals


<https://twitter.com/N3EK80/status/1601878878611738624>

For this ひぐらしのなく頃に fan art illustration, in the sentence "叔父から沙都子を護らねば思っと", is
護らねば another form of "護らなければいけません"?

And in "供述しており", is it common practice for news reporters to use the 謙譲語 form
of おり when talking about criminals or suspects.

