Baker may be a key player in getting FISA warrant and setting up the justification for wiretapping the Trump campaign, too.
For ten years he was with the DOJ Office of Intelligence Policy and Review, seven years as its head. OIPR “supervises the preparation of certifications and applications for orders under FISA”
OIPR is now the National Security Division. FISA is handled by the Operations Section.
https://archives.fbi.gov/archives/news/pressrel/press-releases/james-a.-baker-appointed-as-fbis-general-counsel
https://www.justice.gov/archive/mps/2006omf/manual/oipr.htm
https://www.justice.gov/nsd/office-intelligence
https://www.justice.gov/sites/default/files/pages/attachments/2015/05/20/nsd-org-chart-may2015.pdf