Late Tuesday, the president tweeted his condolences to the victims - except he referred to the deadly incident that occurred at the First Baptist Church in Sutherland Springs, Texas, on November 5, with no mention of California.
The tweet closely mirrored one he sent on November 5 for the victims of the Sutherland Springs shooting.
President Donald Trump faced criticism after he appeared to have copied a tweet shared after a mass shooting earlier this month at a Texas church in the wake of an attack Tuesday that left five people dead and 10 injured in Northern California.
The shooting occurred more than a week ago.
Recently back from Asia, President Trump resumed his morning tweeting routine, this time citing what he's calling a "successful" trip and slamming a regular media target.
Devin Kelley killed 25 people and an unborn child at the First Baptist Church in Sutherland Springs Texas on Nov. 5
Donald Trump has been accused of copying and pasting condolence messages on Twitter after posting about the wrong gun massacre.
Another Twitter user wrote: 'He's mixed up mass shootings, confusing the one last week in Texas with the one in California today.
The California gunman who killed at least four people and hospitalized ten others was identified on Tuesday as Kevin Janson Neal, 43. It was deleted roughly 10 hours later.
The White House did not respond to a request for comment by the Daily Dot about whether Trump mistakenly tweeted about Sutherland Springs instead of the shooting in California.