"I'm not here for the sympathy or the pat on the back, " Mr Heslin told a panel of senators.

BBC: Father of slain Newtown child weeps at Senate gun hearing

Neil Heslin said he came to "speak up" for his son Jesse, 6, who died along with 25 others in Newtown, Connecticut.

BBC: Father of slain Newtown child weeps at Senate gun hearing

The most recent update to the Index shows the sharpest year-to-year rise in clean-energy patents since Heslin began tracking clean-energy innovation trends in 2002.

FORBES: U.S. Clean-Energy Patents Explode in 2010