[1] He was involved in the litigation of human rights cases during that period, and was an active campaigner for Corazon Aquino during the 1986 snap presidential elections.

[6] In 1992, Nograles gave up his congressional seat to make an unsuccessful challenge to the reelection bid of then Davao City Mayor Rodrigo Duterte.

[11] On September 15, 2016, it was reported that Nograles' bodyguards were killed by the Davao Death Squad (DDS) when he ran for mayor against Sara Duterte in 2010.

[12] A confessed DDS member named Edgar Matobato said that the group has kidnapped and killed four supporters of Nograles at the Samal, Davao del Norte, upon the orders of then mayor Rodrigo Duterte.

[13] On March 7, 2017, Nograles faced charges of "graft and malversation" filed by the Ombudsman for allegedly misusing of pork barrel funds for "ghost projects" when he was a caretaker congressman for Misamis Oriental.

The investigation showed that the Department of Budget and Management has released ₱47 million of Priority Development Assistance Fund (PDAF) for the various projects and "bogus" foundations.

According to a report of ABS-CBN News, Karlo Nograles said that his father succumbed to "respiratory failure, secondary to pneumonia".