State Sen. Carlos Uresti was desperate and needed money to pay for his $1.2 million home and fancy cars, prosecutors said during closing arguments Tuesday.
Uresti and co-defendant Gary Cain are charged with a combined 20 federal felony charges.
Prosecutors said Uresti convinced investors to buy into a bogus oil field fracking company called FourWinds Logistics.
Related: Sen. Carlos Uresti: 'I'm not guilty'
Among the investors he is accused of signing up is Denise Cantu, the government's star witness, and a woman who prosecutors called "a shattered, heartbroken, vulnerable woman."
Uresti, who represented Cantu in a multimillion dollar civil suit, is accused of convincing her to invest $900,000 in the defunct company.
Cantu, who testified that she had a sexual affair with Uresti, lost most of her investment, prosecutors said.
Uresti's lawyer, Mike McCrum, said before entering the courtroom that he felt good about the case.
"We're walking in with confidence, with assuredness that the jury is going to listen and take this very seriously," he said. "We're confident on how the evidence came out. It's everything that we thought, and we told everybody."
During closing arguments, McCrum argued that the longtime lawmaker didn't intentionally do anything illegally and had no intent to commit a crime.
McCrum also said that Uresti was misled about the company by CEO Stan Bates, who pleaded guilty to fraud charges last month and is awaiting sentencing.