Former D.C. Council member Michael A. Brown, who said he was caught up in a “culture of corruption running rampant in our city,” was sentenced Thursday to more than three years in federal prison for accepting tens of thousands of dollars in bribes.

The 39-month sentence in U.S. District Court capped a stunning fall for the politically promising son of one of Washington’s most prominent Democratic families.

Chief Judge Richard W. Roberts, who noted that Brown had brought “dishonor on an honored family name,” said that he was “stunned” by Brown’s conduct and that city residents “deserve better.”

“We cannot have our government run this way,” Roberts said before sentencing Brown, whose late father, Ronald H. Brown Jr., was commerce secretary in the Clinton administration and a national Democratic Party leader.

Brown, 49, pleaded guilty in June to accepting $55,000 in cash from undercover FBI agents posing as corrupt government contractors seeking to do business with the city. He was arrested in a hotel conference room in March 2013 after a sting operation that resulted in photos of Brown taking wads of cash in a gym bag, coffee mug and wrapped in rubber bands.

His acceptance of the bribes, prosecutors noted Thursday, occurred about the same time that two other council members — Harry Thomas Jr. and Kwame R. Brown — pleaded guilty to federal corruption charges.

In a statement to the judge, Michael Brown said he should have resisted the corrupt temptations swirling around him and then apologized to family, friends, staff and colleagues. “My parents raised me much better than this, your honor,” he said. “I should have known better than to put myself in this situation.”

Defense attorneys had asked for a sentence of less than three years, telling the judge in a court filing that Brown’s “grave misstep” was “brought about by financial desperation and clouded judgment.”

As a part of his plea agreement, Brown helped investigators in the far-reaching corruption probe that led to the guilty plea of D.C. businessman Jeffrey E. Thompson in March. The former city contractor’s allegation that Mayor Vincent C. Gray (D) knew about Thompson’s off-the-books “shadow campaign” on Gray’s behalf came just weeks before the mayor lost his reelection bid in the April Democratic primary. Gray has not been charged in the investigation.

U.S. Attorney Ronald C. Machen Jr. said Thursday that Brown’s downfall and “decision to auction off the public trust was especially disappointing because of his enormous potential.” After graduating from law school, Brown served as a surrogate speaker during Bill Clinton’s presidential campaigns.

After Ronald Brown died in a plane crash in 1996, his son announced his intentions to “preserve his father’s legacy and follow in his footsteps to public office” in his eulogy at Washington National Cathedral, Brown’s attorneys said in court papers.

Entering the world of D.C. politics, Brown’s attorney Reid H. Weingarten said, meant mixing with influential campaign contributors such as Thompson, who has admitted illegally funneling more than $2 million to a long list of local and federal candidates.

“If he wanted to compete, if he wanted to win in D.C., he had to deal with Jeff Thompson,” Weingarten said.

Brown’s family and friends, some of them prominent political and business leaders, highlighted the former council member’s devotion to his twin sons, his ailing mother and the community in dozens of letters that accompanied his court filing. He asked to be sent to prison in either Florida or Alabama, to be near his grown sons, who are in school nearby.

But prosecutors said Brown’s affinity for “finer amenities and luxuries” led him to financial dysfunction.

From his D.C. Council salary and his employment as a lobbyist, Brown earned more than $220,000 in both 2011 and 2012, according to his tax returns.

But when Brown first met with an undercover federal agent in July 2012, the council member was behind on his taxes and delinquent on his mortgage and car loan payments. He is still deep in debt, his attorneys said.

Brown’s “financial tailspin caused him to take otherwise inconceivable acts given the character that so many closest to him know and recall,” his defense team said.

Brown’s attorneys argued in court papers that he should be shown leniency for strengthening a “central pillar” of the government’s long-running investigation into Thompson. Brown confirmed the businessman’s intent to subvert campaign finance laws.

Prosecutors rejected that argument Thursday, saying that Brown had not been forthcoming about the extent of his involvement with Thompson. Brown initially acknowledged in court papers that he took an illegal $20,000 contribution from Thompson during his failed 2007 run for a council seat. Months later, Brown admitted accepting more than $125,000 from Thompson to boost his successful bid for an at-large council seat in 2008.

Assistant U.S. Attorney Michael Atkinson told Roberts that Brown had “compartmentalized” his cooperation, only admitting to activities that he thought prosecutors already knew about.

Prosecutors also argued that Brown’s actions were part of a pattern that began when Brown was convicted of a misdemeanor in 1997 for making illegal campaign donations.

“This is not the case of an elected official who dipped his toes in the political gutter,” Atkinson said in court. “Michael Brown went all in.”