It's perhaps too easy to forget how many times this has happened. The horrific mass murder at a movie theater in Colorado on July 20, another at a Sikh temple in Wisconsin on August 5, and another at a manufacturer in Minneapolis on September 27 are the latest in an epidemic of such gun violence over the last three decades. Since 1982, there have been at least 62 mass murders* carried out with firearms across the country, with the killings unfolding in 30 states from Massachusetts to Hawaii.

Click HERE for a map of the United States depicting mass murders in the US from 1982 to 2012.

Click HERE for a list of mass murders in the United States from 1982 to 2012 mapped out on the US map, including details on the shooters' identities, the types of weapons they used, and the number of victims they injured and killed.

NOTE: Though the list is not all-inclusive. it is the most comprehensive rundown available on this particular type of traumatic violence. (Mass murders represent only a sliver of America's overall gun violence.) 

Weapons: Of the 139 guns possessed by the killers, more than three quarters were obtained legally. The arsenal included dozens of assault weapons and semiautomatic handguns. (See charts below.) Just as Jeffrey Weise used a .40-caliber Glock to massacre students in Red Lake, Minnesota, in 2005, so too did James Holmes (along with an AR-15 assault rifle) when blasting away at his victims in a darkened movie theater.

The killers: Just under half of the cases involved school or workplace shootings (11 and 19, respectively); the other 31 cases took place in locations including shopping malls, restaurants, government buildings, and military bases. Forty three of the killers were white males. Only one of them was a woman. (See Goleta, Calif., in 2006.) The average age of the killers was 35, though the youngest among them was a mere 11 years old. (See Jonesboro, Ark., in 1998.)

READ MORE AT: Mass Murders In The US and A 30-year timeline of mass shootings, with photos of the killers