Updated at 2 p.m. ET: Former Rep. Jesse Jackson Jr. has signed papers in a plea deal with federal prosecutors in which he admits to violating campaign finance law, according to sources familiar with the case.

In the papers, signed within the past several days, Jackson admits converting campaign contributions for personal use. Some of the violations include using campaign funds for a $40,000 Rolex watch, travel expenses for a friend and furniture purchased for his Washington, D.C., home. Under the terms of the deal, Jackson's sentence would be decided by a federal judge and could range from probation to prison time.

Jackson resigned from the congressional seat he held for 17 years on Nov. 21, 2012, acknowledging a federal investigation and citing health issues.   

"During this journey, I have made my share of mistakes," Jackson wrote in his resignation letter to House Speaker John Boehner, R-Ohio. "I am aware of the ongoing federal investigation into my activities, and I am doing my best to address the situation responsibly, cooperate with the investigators, and accept responsibility for my mistakes, for they are my mistakes and mine alone. None of us is immune from our share of shortcomings or human frailties and I pray that I will be remembered for what I did right."

Those with knowledge of the investigation say some loose ends have yet to be resolved, including questions surrounding whether Jackson's wife, former Chicago Alderman Sandi Jackson, will also be charged in connection with the case. During her husband’s political career Sandi Jackson regularly received a $5,000 a month check as his political consultant, according to NBCChicago.com.

Even before his resignation, Jackson had made plenty of headlines for his mysterious absence from Congress for much of 2012. It was later revealed the son of famed civil rights leader Rev. Jesse Jackson had sought treatment at the Mayo Clinic for bipolar disorder.

Jackson’s resignation came just 15 days after winning re-election to his Chicago-area district by a 40-point margin. President Barack Obama and Chicago Mayor Rahm Emanuel (D) both endorsed Jackson during his primary battle with former Rep. Debbie Halvorson.

Jackson won eight full terms in Congress after winning a special election in 1995.

NBC's Chief Justice Correspondent Pete Williams and Mary Ann Ahern of WMAQ in Chicago contributed to this report.