5 Things To Know This Morning

Sept. 28, 2012 — -- Your look at the five biggest and most buzz-worthy stories of the morning.

1. Shooter Opens Fire Inside Minn. Office, 5 Dead
Officials say a shooter opened fire inside a Minneapolis sign company on Thursday, killing himself and at least four other people. Police officers were dispatched to Accent Signage Systems Incorporated at about 4:35 p.m.

2. 'Innocence of Muslims' Filmmaker Arrested
The California man linked to an anti-Islam film that ignited a firestorm of violent protests across the Muslim world was arrested on Thursday. Nakoula Basseley Nakoula has been under investigation by probation officials who are trying to determine whether he violated the terms of his 2011 prison release on a bank fraud conviction while he was making the film.

3. NFL Refs Back on Field
Official referees were back on the football field Thursday night for the first time since the NFL referee lock out began. When referee Gene Steratore took to the field to greet the captains of the Cleveland Browns and Baltimore Ravens, the stadium erupted into cheers. The NFL and the NFL referees union reached an agreement ending the lock out late Wednesday night.

4. Renoir Found at Flea Market Possibly Stolen
A Renoir painting that was bought at a flea market for $7 may have been stolen from a museum several decades ago. Plans to auction the painting off on Saturday were cancelled after a reporter for The Washington Post found documents in the Baltimore Museum of Art's library showing the piece was on loan there from 1937 until 1951 when it was stolen.

5. Possible Rapidly Moving Stream Found on Mars
The NASA rover Curiosity sent pictures of bedrock that suggest a rapidly moving stream on Mars. The mission's chief scientist calls the discovery exciting. The stream is possibly waist deep.