A study was conducted showing dramatic rise in statistics on gun violence in PG-13 movies. The study shows 94 percent - 420 movies since 1985 - of most watched movies involve at least one violent incident and half of those scenes use gun.

The researchers on the study that was published in the scientific journal Pediatrics this week, analyzed 30 of the top grossing films each year between 1950-2012. The researchers looked into violent scenes in every film and recorded whether the sequences involved a character holding a gun to inflict harm or to kill a specific person.

Violence in movies since 1950 doubled, while the gun violence in PG-13 movies tripled since 1985, more than the quantity found in R-rated movies in recent years.

"Parents need to realize that just because a movie has been rated PG-13 does not mean that their 13-year-old should go to see it," Daniel Romer, author of the study claimed. "We would like to see Hollywood go back to labeling movies with lots of violence, and gun violence in particular, with an R rating, just like they have been doing for explicit sex all along."

On the average, an American sees seven films every year, according to the statistics shown by Nielsen's 2012 American Moviegoing Report. The PG-13 movies are most likely the highest grossing with 45 percent market share.

Motion Picture Association of America first used the PG-13 rating in 1985, with the intention of urging the parents to be cautious however, movie theaters do not normally inspect IDs for moviegoers.  

"There has been a long line of research showing that continued exposure to screen violence among children, mainly on TV, predicts the emergence of later aggressive behavior," Romer explained. "We don't know if seeing gun violence on the screen has a unique effect, but it is concerning considering that we have seen a rise in the use of guns in schools and other settings in recent years."

 "We do not draw a direct causal link to the recent rise in school and other public shootings, but the rise in gun violence in films certainly coincides with those events," he added.

In comparison, the gun violence in movies with R- and G/PG rating did not increase. R- rated movies maintain their rate in violent sequences while G- and PG-rated movies decreased over the same timeline.