Gun Control & RKBA

depending on what data set you look at. The Chicago police department puts it at 87% of murderers had prior arrest records in Chicago, presumably not counting other jurisdictions.

http://home.chicagopolice.org/wp-content/uploads/2014/12/2011-Murder-Report.pdf

The Federal BJS puts the nationwide number at 74%.

http://www.bjs.gov/content/pub/pdf/mf.pdf

Keep in mind that "gang violence" typically refers to gang warfare, not to all criminal violence perpetrated by people affiliated with gangs.

Here are some more stats to keep in mind when discussing outlawing the most popular rifles in U.S. homes:

Murder, by State and Type of Weapon, 2014 (FBI)

[font face="courier new"]Total murders...................... 11,961
Handguns............................ 5,562 (46.5%)
Firearms (type unknown)............. 2,052 (17.2%)
Clubs, rope, fire, etc.............. 1,610 (13.5%)
Knives and other cutting weapons.... 1,567 (13.1%)
Hands, fists, feet.................... 660 (5.5%)
Shotguns.............................. 262 (2.2%)
Rifles................................ 248 (2.1%) [/font]

Rifles are consistently the least misused of all weapons, usually accounting for less than 300 of the nation's 12,000 murders annually.