BOSTON (Reuters) - The Brady Campaign to Prevent Gun Violence said on Friday it has sharply cut back an online ad that had used the names and faces of mass shooters and urged the news media not to identify them after the group drew criticism from other gun control activists.

Guns are seen inside a display case at the Cabela's store in Fort Worth, Texas, in this file photo dated June 26, 2008. REUTERS/Jessica Rinaldi

The group, named for former White House spokesman James Brady, who was wounded in 1981 when a gunman tried to assassinate then-President Ronald Reagan, rolled out the “Zero Minutes of Fame” campaign earlier this week.

Its goal, the group said, was to promote research showing that mass shooters, such as those who carried out the 2012 attacks in Newtown, Connecticut and Aurora, Colorado, had studied past gun attacks before carrying out their own.

The prominent use of the names and images of Adam Lanza, who shot dead 20 children and six educators at a Newtown elementary school, and James Holmes, who fatally shot 12 people at an Aurora movie theater, in the two-minute online spot angered fellow anti-gun-violence campaigners.

The Brady Campaign's ad prompted a petition (chn.ge/1SCfovp) on activist website Change.org calling for the ad to be taken down. Some 93 people had signed that petition as of midday Friday.

“It was very hurtful to many gun violence victims and survivors,” said Anita Busch, a Los Angeles-based entertainment journalist whose cousin was slain in the Aurora massacre and who said she posted the petition. “For the Brady Campaign to not get it is just shocking, honestly.”

The ad marked the launch of a piece of software for Google's GOOGL.O Chrome web browser that promised to remove the names and images of serial killers from news accounts and Google web searches, replacing them with "(name withheld out of respect for the victims)."

The Brady Campaign, one of the most prominent U.S. gun control organizations, said on Friday it had cut back the ad’s contents after the complaints. A 14-second version of the ad viewed on Friday featured no names or images of mass shooters.

“Our video was meant to educate the broader American public about what we can do to prevent gun violence, not to upset those hardest hit by it,” Dan Gross, the group’s president, said in an e-mailed statement. “We take this matter seriously and hope the steps we have taken to fix this are satisfactory to our victim advocates.”

James Brady survived the 1981 attack and went on to become a prominent gun control activist. He died in 2014.