Man pages matching name proc::killfam in section 3pm:

Proc::Killfam.3pm.en	debian 10 / libproc-processtable-perl
Proc::Killfam.3pm.en	debian 11 / libproc-processtable-perl
Proc::Killfam.3pm.en	debian 12 / libproc-processtable-perl