Later clips of the upcoming series "Deception" featured several shots of a bloodied, dead body.
NBC also is developing a drama, "Hannibal," based on one of fiction's most indelible serial killers, Hannibal Lecter. An airtime for the show hasn't been scheduled, but it could come this spring or summer.
Salke said there is more violence in Fox's upcoming drama "The Following," also about a serial killer, than there will be in "Hannibal." Much of the violence in the upcoming NBC show, created by former "Heroes" producer Bryan Fuller, is implied and not gratuitous.
"We respect the talent and like what he is doing, so we are standing behind him," Salke said. She said there's been a spate of programs about creepy killers because they've been such indelible characters.
Greenblatt said he wasn't trying to be glib, but one of the best tonics for people upset about real-life violence is to watch an episode of NBC's "Parenthood." He said it's a great example of a family that loves each other and grapples with many issues.
"Ultimately, I think you feel good at the end of the day," he said.