Families of victims of mass shootings in America have appealed to the media not to show pictures of the gunmen involved, because they say it encourages copycats.

The issue has come to a head in the trial of the man who admits killing 12 and wounding 70 others in a Colorado cinema.

Alex Teves was one of those killed. His parents Tom and Caren formed the 'No Notoriety' campaign and have written to 150 US media companies asking them to focus on the victims rather than the shooter.

They say the issue is a matter of "public safety".

Mr Teves said: "There is nobody in this country who doesn't know who that thing is or what that thing looks like."

"As you sensationalise him, other cowards who have no lives...are going to run out and get a gun so they can get on your show next week."

The trial started last month, with the gunman pleading not guilty due to insanity.

Dozens of journalists and camera crews have been camped out at the court in Centennial, and almost all have used photographs of the defendant in their reports.

Larry Rykman, the city editor of the Denver Post, says he sympathises with the family, but it is not possible to have a blanket ban on identification.

"It's difficult for all of us. We have our jobs to do as journalists and while we understand the pain that it brings them to hear the defendant's name, it's also our job to cover this trial."

"There have been stories we've done that haven't mentioned the name of the shooter and we have tried to be sensitive in terms of thinking twice about when we use his photo, and when we don't."

"It would be very easy to use a photo of him with shock orange hair with every story. We've chosen not to do that."

The Teves family have been supported by dozens of relatives of those killed or injured at other mass murders, such as the Virginia Tech shooting and the one at Sandy Hook elementary school.

They want the media to adopt new guidelines for future mass murders. The guidelines state: "Remove the shooter's name from headlines."

"Remove or limit the name and likeness of the shooter, except for initial identification and when the alleged assailant is still at large and in doing so would aid in his capture."

"Refuse to run self-serving manifestos unless doing so will aid in the individual's capture."

"Elevate the names and likenesses of all victims killed to send the message their lives are more important than the shooter."

When it was suggested that changing America's gun laws might be the most effective way of preventing such incidents, Mr Teves said: "You want to shift the blame to someone else instead of taking ownership and doing something yourself that you can do."

"I don't even want to get into guns. Guns have nothing to do with this."