What did Marilyn Mosby know about her and ex-husband Nick Mosby’s tax debt? When did she know it? Did she know she owed the Internal Revenue Service $69,000 when she filled out paperwork to purchase luxury vacation homes in Florida? Can the jury know she is a convicted perjurer?

Those questions are crucial to the former Baltimore State’s Attorney’s defense in her upcoming mortgage fraud trial, and lawyers for Mosby have traded salvos of legal filings with federal prosecutors in recent weeks to determine what kind of evidence can and can’t be presented to the jury in Prince George’s County on Jan. 18.

January’s trial is Marilyn Mosby’s second and will come two years after a grand jury indicted her on charges of mortgage fraud and perjury. A jury convicted Mosby on the perjury charges in November, finding she lied on a form about experiencing financial hardship during the COVID-19 pandemic in order to make early withdrawals from her city retirement account — money she used to buy a pair of Florida properties.

Those properties — an eight-bedroom house with a pool in Kissimmee, Florida, near Disney World, and a seaside condo on the Gulf Coast — are at the center of the government’s mortgage fraud case against Marilyn Mosby. Prosecutors say she lied on the mortgage applications for both, including about whether she owed money to the IRS, how much money she had available to her and where it was coming from.

U.S. District Judge Lydia Kay Griggsby on Friday ruled that prosecutors can’t tell the jury about Marilyn Mosby’s perjury conviction, because doing so would unfairly prejudice the jury against her.

“The various issues in this case will be forgotten when the jury looks at what they’ve been told is a convicted liar,” Federal Public Defender James Wyda said in court.

However, if Marilyn Mosby decides to testify in this case (she declined to do so at her perjury trial), prosecutors would be able to ask her whether she has been convicted of perjury. Mosby could either answer that question “yes,” or exercise her Fifth Amendment rights and be silent.

“To deprive a jury of knowledge that a defendant had been convicted of perjury would mean to deprive them of the most important thing to ascertain her credibility,” Assistant U.S. Attorney Aaron Zelinsky said.

Griggsby, siding with prosecutors, blocked the defense from introducing out-of-court statements made by Baltimore City Council President Nick Mosby in which he takes responsibility for handling the couple’s tax lien, as well as most statements Marilyn Mosby made to her mortgage broker and bankers about the tax debt and a rental agreement she had for one of the homes.

An area banker, named in court filings as J.H., told investigators in 2021 that Nick Mosby called the bank in 2020 seeking a loan to pay off the couple’s tax debt. Asked why Marilyn Mosby wouldn’t also be on the loan, J.H. recalled Nick saying, “It’s my obligation. I want to take care of it,” according to court filings.

The couple’s divorce finalized in November, according to court records, but it’s possible the defense will call Nick Mosby as a witness in the case.

Statements recalled by another person are considered hearsay in court, but can be admitted under certain circumstances. Prosecutors wrote in court filings that the statements people recalled hearing the Mosbys make may be fake, or at least misleading, because it was widely known that the couple were under investigation.

Griggsby said because the statements were made in spring of 2021, well after Marilyn Mosby had filled out her mortgage applications, they couldn’t get to what she thought or knew about her tax debts at the time she purchased the homes.

One statement, a text from Mosby to an unnamed mortgage broker, is allowable because it doesn’t make an assertion, Griggsby said. However, the judge left the door open for prosecutors to try again.

The defense sought to limit the government from telling the jury about letters the IRS sent the Mosbys because those would ostensibly prove she knew about the tax debt before she purchased the homes. Griggsby denied that request.

The mortgage fraud is about more than whether Marilyn Mosby properly disclosed her tax debt to her loan providers. There were other issues, including about how she planned to use the Kissimmee house. Marilyn Mosby signed what’s known as a second home rider, according to publicly available mortgage documents, which means she had to maintain control of the house for a year.

Instead, she signed an agreement with a vacation property management company that could rent the home out, according to court records. Had Mosby disclosed she planned to use the home for business purposes, the bank would have likely required a higher down payment.

In another instance, according to court filings, Marilyn Mosby told the bank in December 2020 she had been living in Florida for 70 days at the house near Disney, despite the fact she was in the middle of her second term as the elected prosecutor in Baltimore and that she had signed a rental agreement for that property.

In addition to her criminal troubles, Marilyn Mosby is on the verge of losing her law license. Maryland Bar Counsel, the entity that investigates lawyers for misconduct, asked the state supreme court last month to revoke her law license, and earlier this week the court ordered her to explain why she shouldn’t.