Pipe bomb packages suspect Cesar Sayoc (Photo: Screenshot from NBC News)

Pipe-bomb suspect Cesar Sayoc on Monday made his first appearance before a federal judge in Miami, as law enforcement sources revealed that he kept a list of more than 100 potential targets, NBC News reported.

For now, Sayoc has been charged with five federal crimes connected to his alleged mailing of 14 pipe bombs to a wide variety of people who have been critical of President Trump, and he faces 48 years in prison if convicted of all charges, according to NBC News.