JPMorgan Chase and the Justice Department have reached a tentative $13 billion settlement over the bank’s questionable mortgage practices leading up to the financial crisis, people briefed on the talks said Saturday. It would be a record penalty that would cap weeks of heated negotiating and underscore the extent of the bank’s legal woes.

The deal, which the Justice Department took the lead in negotiating and which came together after a Friday night call involving Attorney General Eric Holder and JPMorgan’s chief executive, Jamie Dimon, would resolve an array of state and federal investigations into the bank’s sale of troubled mortgage investments. That type of investment, securities typically backed by subprime home loans, was at the heart of the financial crisis.

While the deal would put those civil cases to rest, it would not save JPMorgan from a parallel criminal inquiry from federal prosecutors in California, the people briefed on the talks said. Under the terms of the preliminary deal, the people said, the bank would also have to assist prosecutors with an investigation into former employees who helped create the mortgage investments.

The $13 billion deal, which could still fall apart over issues like how much wrongdoing the bank is willing to acknowledge, would represent something of a reckoning for Wall Street, whose outsize risk taking in the mortgage business nearly toppled the economy in 2008. It might also provide a measure of catharsis to the investing public, which suffered billions of dollars in losses from buying bad mortgage securities.

For the Justice Department, often criticized for being soft on big banks, the deal suggests that the Obama administration’s crackdown on Wall Street has gained some momentum in recent months. It comes less than three months after federal prosecutors and the FBI in Manhattan announced a criminal indictment of the hedge fund SAC Capital, which was accused of permitting a “systematic” insider-trading scheme to unfold from 1999 to 2010. The hedge fund, according to people briefed on the case, is negotiating a plea deal that would force it to plead guilty to criminal misconduct and pay more than $1 billion in penalties.

The cost to JPMorgan, the nation’s biggest bank, goes beyond the bottom line. The settlement would deal a reputational blow to the bank and Dimon, who steered JPMorgan through the crisis without a quarterly loss or major government scuffle. Now Dimon’s tenure is engulfed in turmoil, the consequence of fighting a multifront battle with federal authorities scrutinizing everything from a $6 billion trading loss in London last year to the bank’s hiring of well-connected employees in China.

In the mortgage case, the size of the penalty underpins its importance. The $13 billion penalty, according to one of the people briefed on the talks, would include about $9 billion in fines and $4 billion in relief for struggling homeowners.