James Holmes stands accused of opening fire in a packed cinema in Aurora in the early hours of Friday morning at a midnight screening of the final Batman movie in Christopher Nolan's trilogy, The Dark Knight Rises.
As the news of the incident spread, Playboy model Tricia Evans raised further controversy after tweeting that the new Batman movie was "to die for".
While many celebrities have taken to Twitter to voice their horror at the incident and to show their support for the victims and their families, others, like Seinfeld star Jason Alexander, have been caught in a wave of criticism for airing their views about America's gun culture.
Less than 24 hours after the shooting occurred, Tricia tweeted:
I heard the new Batman movie is really "to die for"! ?? Too soon?— Tricia Evans (@HollywoodTricia) July 20, 2012
good to know. @HollywoodTricia i seriously had no idea how big of a piece of shit you are. unfollowed.— deadmau5 (@deadmau5) July 20, 2012
Evans then wrote Deadmau5 (real name is Joel Zimmerman), "Listen, apparently I have a different opinion than u. That doesn't make me a piece of shit," to which he responded, "so your opinion of the tragedy in Colorado is... 'humor'? not sure how that's convoluted into an opinion."
The blonde centrefold has continued to hold court on Twitter as her followers have come out to both slam and support her.
Tricia also criticised parents who take their children to late-night movie screenings. The youngest victim of the Colorado cinema shootings was a six-year-old girl, whose pregnant mother remains in critical condition in hospital.
Christopher Nolan and Dark Knight Rises star Christian Bale have both released statements about the tragedy, with Bale saying: "I cannot begin to truly understand the pain and grief of the victims and their loved ones, but my heart goes out to them."
Suspected killer Holmes on Monday made his first court appearance since his arrest and prosecutors say they are considering pursuing the death penalty.