Philadelphia police officers held a silent vigil to honor a slain officer while his convicted killer delivered a commencement speech at a Vermont College on Sunday.

Former death row inmate Mumia Abu-Jamal is serving a life sentence for the 1981 murder of white Police Officer Daniel Faulkner. However, the former Black Panther claims that he is innocent and has gained international support as a political prisoner.

On Sunday, 20 graduating students at the Goddard College in Plainfield listened to his speech by video, which encouraged the grads to strive to transform the world now that they have achieved a bachelor's degree.

"Think about the myriad of problems that beset this land and strive to make it better," Abu-Jamal said in the video, according to WKRC.

Abu-Jamal, who attended the college in the 1970s and earned his degree in 1996, said that "Goddard reawakened in me my love of learning."

However, as the students were listening to a recording of his speech, Philadelphia police officers and supporters held a silent vigil to honor officer Faulkner's life.

Head of the Philadelphia chapter of the Fraternal Order of Police John McNesby also bashed the liberal college's decision to make the inmate their commencement speaker and criticized the school's student-driven curriculum, which involves faculty advisers and excludes tests and a grading system.

"Apparently this is a school up there where they don't grade you, there's no teachers, there's advisers. So I don't know who's advising them, but obviously they're not doing a good job," told WPVI-TV.

The decision to allow Abu-Jamal to speak also angered the Vermont Troopers Association, which argued that it showed a disregard for the victim's family.

On the other hand, Goddard College described Abu-Jamal as "an award winning journalist who chronicles the human condition" and stated that he was selected as a way to let students "engage and think radically and critically."