First Circuit: US v. Irizarry-Rosario

References in closing to potentially aggravating factors do not breach  the plea deal, so long  as the tactic is not an end run around the plea agreement, and the government doesn't express regret or a desire to be free of the terms of the deal.

http://media.ca1.uscourts.gov/pdf.opinions/17-1117P-01A.pdf