By Keith Coffman
DENVER, April 24 (Reuters) - A conservative advocacy group has pulled a photograph used in an attack ad against Democratic U.S. Senator Mark Udall that depicted him with a grim-faced President Barack Obama in the aftermath of the Colorado theater massacre, after victims' families complained.
The TV ad, paid for by Americans for Prosperity, the political group funded by billionaire brothers David and Charles Koch, showed a photograph of the first-term senator with Obama, linking Udall to the president's unpopular Affordable Health Care Act.
The photo is a captured screen shot taken from a news conference that Obama, Udall and Colorado Governor John Hickenlooper held shortly after the three Democrats met with victims of the mass shooting in July 2012.
The cropped photograph used in the ad cut Hickenlooper out of the photo, leaving just the image of a somber-looking Udall alongside Obama. A message superimposed over the image reads: "Mark Udall voted for Obamacare."
The parents of four victims slain in the massacre denounced the ad as "an utter disgrace."
"(T)o insinuate the somber expressions were for anything other than their compassionate response to our heartbreak is beyond unconscionable," the families said in a statement. "Americans for Prosperity is exploiting our tragedy for political gain."
Dustin Zvonek, executive director of Americans for Prosperity's Colorado chapter, said the group pulled the photograph from the ad after learning of its origin.
"This was an unfortunate oversight and as soon as we heard about it, it was taken down," Zvonek said. "We sincerely apologize to the Aurora families, but the purpose was about the senator's support for Obamacare, not the shootings."
Udall, who is in a close race to retain his seat this fall, urged his presumptive Republican opponent, U.S. Representative Cory Gardner, to stop using the theater shooting for political gain. Gardener distanced himself from the ad.
"As Senator Udall knows, our campaigns have nothing to do with the creation of outside advertisements," Gardner said. "That being said, the use of this picture was insensitive and wrong, and I am glad to hear that it has been taken down."
A Quinnipiac University poll released on Thursday showed the Senate race in a dead heat, with Udall holding a 1 percentage point lead over Gardner. The same poll showed that the Affordable Health Care Act is unpopular in Colorado, with 59 percent of respondents opposing the law. (Editing by Cynthia Johnston and Lisa Shumaker)