(Bloomberg) -- Martin Shkreli, clad in prison fatigues and sporting a scruffy beard, returned to court for the first time since his jailing in September, hoping to convince a judge that he shouldn’t have to forfeit money to the U.S. government.

For 90 minutes in federal court in Brooklyn, New York, on Friday, Shkreli fidgeted and occasionally smirked as his legal team assailed the prosecutor’s request that he surrender $7.4 million he allegedly reaped from his frauds. His mother, Katrina, was also in court for the first time since her son’s December 2015 arrest.

Now with prison-issued glasses instead of the wireless spectacles or contacts he sported at trial, Shkreli listened closely as his lawyer argued that he generated "robust returns" for his hedge fund investors, didn’t steal their money, and shouldn’t have to pay a cent.

"At the end of the day, investors made substantial amounts of money," defense lawyer Benjamin Brafman told the judge.

It was a far cry from Shkreli’s behavior at his trial last summer, when he rolled his eyes during testimony from government witnesses and hurled angry outbursts at reporters. He appeared to realize that the ruling by U.S. District Judge Kiyo Matsumoto would not only determine what he owes but will influence how much time he spends behind bars. Shkreli’s sentencing, scheduled for March 9, will be based in part on the amount of investor losses.

Shkreli, a 34-year-old hedge-fund-manager-turned-biotech-founder, was accused of defrauding investors in his funds, losing their money in bad trades, and paying them back with assets from the drug firm he launched, Retrophin Inc. He was convicted in August of lying to the investors and scheming to manipulate the drug firm’s shares, but acquitted of stealing from the company.

Martin Shkreli’s Fall: Why ‘Most-Hated’ CEO Is Strutting to Jail

The judge didn’t rule on the forfeiture amount, but she did reject Shkreli’s request to toss out his conviction. Despite his argument that prosecutors misled jurors about the law, the evidence presented at the trial was "was more than sufficient" to warrant a conviction, Matsumoto told lawyers.

Matsumoto ordered Shkreli jailed in September for issuing a bounty on social media for a sample of former Secretary of State Hillary Clinton’s hair.

Shkreli’s assets include a Picasso, $5 million in his personal trading account, a one-of-a-kind special edition album by the Wu-Tang Clan and his shares in Vyera Pharmaceuticals -- formerly called Turing Pharmaceuticals, according to prosecutors.

Prosecutors on Friday argued that Shkreli cost his investors more than $20 million by inducing them to put millions of dollars into his two hedge funds which operated essentially like Ponzi schemes. Assistant U.S. Attorney Alix Smith said he spent investor funds on personal expenses "to maintain the image of a successful hedge fund manager."

"The monies Shkreli got from his investors were the lifeblood of his fraud schemes," Assistant U.S. Attorney Claire Kedeshian said. "Like a bandit or a thief, he took money from one to pay off another and used it for his own benefit."

Matsumoto skeptically questioned Brafman’s argument that Shkreli should get credit for repaying investors in his failed hedge funds with Retrophin shares -- which the defense says eventually paid out substantial profits.

"What you’re saying is any convicted fraudster could never face forfeiture as long as they used the money in something that went completely bust," said the judge, who didn’t immediately rule.

--With assistance from Christie Smythe

To contact the reporter on this story: Patricia Hurtado in Federal Court in Manhattan at pathurtado@bloomberg.net.

To contact the editors responsible for this story: David Glovin at dglovin@bloomberg.net, Peter Blumberg

©2018 Bloomberg L.P.