Revenge may have motivated Russian President Vladimir Putin to target American democracy; the U.S. confronts Putin about Russian involvement in the 2016 election.

The inside story of Russian President Vladimir Putin's conflict with the U.S., including his grievances and efforts to exact revenge.

"Mosul" and "Inside Yemen" are both in this two-part hour per Frontline website.

"Mosul" - Described by some military commanders as the deadliest urban combat since World War II, the battle to drive ISIS out of Mosul, Iraq was brutal and grueling. Shot over the course of the nine-month battle, "Mosul" follows four young Iraqi special forces soldiers tasked with leading the fight.

"Inside Yemen" - An up-close look at how Yemen's humanitarian crisis was worsened by a brutal war.

How Scott Pruitt went from fighting EPA to running the agency and rolling back years of policy.

Who killed Kim Jong Un's half-brother, Kim Jong Nam, and what does the murder reveal about the North Korean leader and his intentions and his regime and its capabilities?

Following the 2008 financial crisis, the only U.S. bank to face criminal charges was Abacus Federal Savings Bank, the first Chinese-owned bank in New York's Chinatown. Founded by immigrant Thomas Sung in 1984 and now run by him and his American-born daughters, the bank was accused of mortgage fraud in a legal battle that spanned five years costing them $10 million. From acclaimed director Steve James, the little-known story of the only U.S. bank prosecuted in relation to the 2008 financial crisis. Now an Academy Award nominee for Best Documentary Feature.

With unique access, go inside an effort in Connecticut to change the way parole works and reduce the number of people returning to prison. In collaboration with The New York Times, the film follows four former prisoners as they navigate the challenges of their first year on parole.

The inside story of Trump adviser Stephen Bannon's war — with radical Islam, Washington, and White House rivals as he works to deliver on President Trump's campaign promises.

FRONTLINE investigates how the Bundy family's fight against the federal government invigorated armed militias and "patriot" groups — helping them grow to levels not seen in decades.

FRONTLINE and NPR investigate the billions spent on affordable housing for the poor, and why so few get the help they need.

Inside the fight over the fate of juveniles in prison for murder, following a landmark Supreme Court ruling.

Journalist, best-selling author and lifelong fisherman Paul Greenberg spends a year traveling from Norway to Peru investigating the health of the ocean. He eats only fish at breakfast, lunch, and dinner to help answer the question: "What fish should I eat that's good for me and good for the planet?"

Inside one state's ambitious attempt to decrease its use of solitary — and what happens when prisoners who have spent considerable time in isolation try to integrate back into society.

Venture inside Iraq, as militias and the military fight for the future of the country. FRONTLINE investigates allegations of abuse of Sunni Muslim civilians by powerful Shia militias.

FRONTLINE and NPR examine the struggle over freeing prisoners once deemed international terrorists. This includes the dramatic story of a Gitmo detainee released from the controversial U.S. prison after 14 years. Also in this two-part hour: "Forever Prison," a collaboration with Retro Report exploring the untold history of the Guantanamo Bay prison.

Reporter Ghaith Abdul-Ahad goes inside the battle against ISIS for control of the city of Mosul. See what's happening in areas where ISIS has been ejected and investigate forces shaping Iraq. Also in this two-part hour: "Hunting ISIS," a dramatic report on an Iraqi unit at the center of the fight.

An investigation of how Donald Trump defied expectations to win the presidency — and what it suggests about how he will govern.

An examination of the key moments that shaped President-elect Donald Trump. Interviews drawn from "The Choice 2016" with advisors, business associates and biographers reveal how Trump transformed himself from real estate developer to reality TV star to president.