James E. Holmes

Unhindered by federal background checks or government oversight, the 24-year-old man accused of killing a dozen people inside a Colorado movie theater was able to build what police called a 6,000-round arsenal legally and easily over the internet, exploiting what critics call a virtual absence of any laws regulating ammunition sales. With a few keystrokes, the suspect, James E. Holmes, ordered 3,000 rounds of handgun ammunition, 3,000 rounds for an assault rifle and 350 shells for a 12-gauge shotgun — an amount of firepower that costs roughly $3,000 at the online sites in the four months before the shooting.