Know It All: Wednesday evening's top stories on NBC News

Iranian President Hassan Rouhani in the leader's first interview with a U.S. news outlet since becoming president. Ann Curry / NBC News

Here's a snapshot of some of the top stories we're following Wednesday evening:

Iran's President Rouhani: We will never develop nuclear weapons

Iranian President Hassan Rouhani told NBC News that the country will never develop nuclear weapons and that he has the clout to make a deal with the West on the disputed atomic program. Read more on NBC News

"We didn’t use any chemical weapons," Assad says

In another interview with a U.S. news outlet, Syrian President Bashar Assad once again denied his military forces were responsible for deploying sarin gas in an horrific attack that sparked threats of a U.S. strike and was this week confirmed by the United Nations. Read more on NBC News

Navy Yard gunman's mom: 'I'll never be able to ask him why'

The mother of Aaron Alexis, the Washington Navy Yard shooter, said Wednesday that she was heartbroken and sorry for the families of the victims and that she was glad he is "in a place where he can no longer do harm to anyone." Read more on NBC News

Stocks spike as Fed maintains stimulus

Stocks finished sharply higher Wednesday, with the Dow and S&P 500 logging fresh highs, after the Federal Reserve surprised Wall Street by keeping its $85 billion-a-month bond-buying stimulus program intact. Read more on NBC News

After bodies discovered in Okla. lake, closure could take years in cold cases

It could be years before the six people whose skeletal remains were discovered in two cars at the bottom of an Oklahoma lake are positively identified, authorities said — but they were pretty sure the discovery will solve two 40-year-old missing persons cases. Read more on NBC News

Donations pour in for homeless man who returned backpack with $42K

Honesty really paid off for a homeless man in Boston who turned in a backpack worth nearly $42,000 earlier this week. Since his good deed, an online fundraiser had raised more than $73,000 for Glen James by Wednesday afternoon, and brought in offers from strangers who want to help the Good Samaritan by donating computers and offering health care services to him. Read more on NBC News

Abducted Georgia girl, 14, found alive, officials say

A 14-year-old Georgia girl kidnapped by two gunmen during a home invasion early Tuesday has been found alive, officials said. Read more on NBC News