He's also said to be planning a press event near the apartment of suspected murderer James Holmes following a nationwide series of gun-violence gatherings over the weekend.
According to Rainbow PUSH Coalition, prayer vigils were held in El Paso, Texas, Boston, Massachusetts, Winston-Salem, North Carolina, San Francisco, California, Birmingham, Alabama, Oklahoma City, Oklahoma, Harrisburg, Pennsylvania, Detroit, Michigan and (update) Chicago, Illinois, with Jackson taking part in the latter.
We've got messages in to Rainbow PUSH to get more details; we'll update this post when and if we hear back. In the meantime, here are some vigil photos from the Rainbow PUSH Facebook page.
More from our Aurora Theater Shooting archive: "James Holmes: Inside the courtroom with shock-haired Aurora theater shooting suspect."