Prosecutors cherry-picked evidence, blindly accepted the shifting accounts of accusers and had not proven its case against Ghislaine Maxwell, a defense lawyer told the jury as Ms. Maxwell’s sex-trafficking trial neared its end on Monday.

In a closing argument that was by turns biting, sarcastic and indignant, the lawyer, Laura Menninger, urged jurors to reject the government’s arguments and to be skeptical of evidence she called thin and witness testimony she said was flimsy.

“The government wants you to speculate, over and over,” Ms. Menninger said, later adding: “Ms. Maxwell does not have to prove her innocence to you. You already know it.”

In addition to assailing the government’s case and the motives and memories of Ms. Maxwell’s accusers, Ms. Menninger took aim at Jeffrey Epstein, whom she said the trial had proven to be a “master manipulator.”

“Everyone knew Jeffrey was keeping secrets from Ghislaine, except Ghislaine,” Ms. Menninger said, noting the household staff and pilots had concealed Mr. Epstein’s other girlfriends from Ms. Maxwell.

Near the end of her closing argument, Ms. Menninger said Ms. Maxwell was on trial because of her relationship with Mr. Epstein. “Maybe that was the biggest mistake of her life, but it was not a crime,” she said.

Ms. Menninger spent the bulk of her two hour and 15 minute closing walking the jury through the testimony of the four women who took the stand to accuse Ms. Maxwell of grooming them for sexual abuse when they were teenagers.

She pointed out inconsistencies in their testimony — particularly where it did not align with their previous statements to law enforcement officials, or with their contemporaneous accounts.

She also focused on the financial settlements the witnesses had received from Mr. Epstein’s estate. She described the lawyer of one victim as “no dummy,” saying that after Mr. Epstein was dead the lawyer knew there was a “pile of cash” to pursue for his client.

“All of these witnesses have changed their stories many times,” Ms. Menninger said. “Why?”

Ms. Menninger argued the government’s case rested on the “erroneous memories” of the four women. She relied on the testimony of one defense witness, an expert who testified about the malleability of memory. “Memory weakens over time and memory can be impacted and corrupted by post-event contamination,” Ms. Menninger said.

“How vivid a memory seems does not make it more accurate,” Ms. Menninger said.

Ms. Menninger attacked the credibility of other government witnesses as well. She described one witness — a former employee who described Ms. Maxwell as the “lady of the house” who set the rules for Mr. Epstein’s home — as “a two-time burglar, obviously with an ax to grind.”

She pointed to the felony convictions and drug use of another witness, the former boyfriend of one of the accusers.

Ms. Menninger also pushed back sharply against prosecutors’ contention — in opening statements and in closing arguments — that Ms. Maxwell’s participation in Mr. Epstein’s scheme was motivated by money and maintaining her luxurious lifestyle.

A prosecutor earlier in the day cited bank records that showed Mr. Epstein transferred $30.7 million to Ms. Maxwell between 1999 and 2007, which includes some of the years in which she has been charged with helping him to recruit, groom and sexually abuse young teenagers.

“The government makes a big show of these big dollar transfers,” Ms. Menninger said. “That is some thin testimony,” she continued.

She said the prosecution was asking the jury to speculate. “Speculation is not evidence,” Ms. Menninger said, adding it was not even clear that Ms. Maxwell “knew that these transfers were being made in her name.”