The video was on display at a conference organised by American Priority, a pro-Trump group, the BBC reported.
Organisers of the event at a Trump resort in Miami, Florida, said the video was part of a "meme exhibition".
Tim Murtaugh, a spokesman for the Trump campaign, told the New York Times: "That video was not produced by the campaign, and we do not condone violence."
In the video, Trump's head is superimposed on the body of a man who goes on a killing rampage inside "the Church of Fake News".
The heads of the people he kills have been replaced with the logos of media organisations, including the BBC, CNN and the Washington Post, and political opponents such as his predecessor Barack Obama and former presidential hopeful Hillary Clinton.
American Priority also sought to disassociate itself with the video, saying it was "not approved, seen, or sanctioned" by event organisers.
The video, the political action group added, was shown in a "side room" at the event and was only brought to the attention of organisers by the New York Times.
During his 2016 presidential campaign, and as President, Trump has repeatedly lashed out at what he calls the "fake news media", describing media outlets as "enemies of the people", the BBC said.
In recent weeks, Trump ramped up his attacks on his political rivals and media organisations as an impeachment inquiry launched by the House Democrats on September 26 into his presidency has escalated.
A similar parody video was shared on Trump's Twitter page in 2017.
The clip was an altered version of Trump's appearance at a WWE wrestling event in 2007, in which he "attacked" franchise owner Vince McMahon. In the video, a CNN logo appeared in place of McMahon's head.
( With inputs from IANS )