Bollywood superstar Amitabh Bachchan
"Each day something disturbing appears. Saw live footage of Colorado killings... gunman dressed as Batman saying he was 'the Joker'," Big B tweeted.
The man had a rifle, a handgun and a gas mask when police arrested him. The incident has shocked people across the world and Indian celebrities, including actress Madhuri Dixit, who stayed in Denver after her marriage in 1999, and jewellery designer Farah Khan Ali, have condemned it.
"My heart goes out to the families," tweeted Madhuri.