Bill pardoned Marc Rich on his last day in office. Rich was a fugitive from the Department of Justice and one of the FBI's most wanted at one point. The FBI investigated because Rich was a major political donor to the DNC, and the FBI thought somehow those donations may have been played a part in his pardon.
https://www.yahoo.com/news/fbi-releases-bill-clinton-closed-case-files-days-232844166.html
From the article:
Some of the donations went to the William J. Clinton Presidential Foundation, the predecessor to the Clinton Foundation, according to the document.
"It appears that the required pardon standards and procedures were not followed," reads the FBI document dated February 15, 2001.
The Rich case fell under the watch of current FBI Director James Comey, then a younger prosecutor.
https://www.yahoo.com/news/fbi-releases-bill-clinton-closed-case-files-days-232844166.html
From the article:
Some of the donations went to the William J. Clinton Presidential Foundation, the predecessor to the Clinton Foundation, according to the document.
"It appears that the required pardon standards and procedures were not followed," reads the FBI document dated February 15, 2001.
The Rich case fell under the watch of current FBI Director James Comey, then a younger prosecutor.