Both parties rested their cases in the post-conviction hearing of Adnan Syed in Baltimore on Monday. The proceedings began dramatically with FBI special agent Chad Fitzgerald claiming that Syed’s defense had given him “manipulated evidence” in order to throw off his testimony. “I figured out what you were doing,” Fitzgerald said to C Justin Brown, Syed’s attorney. “You got caught in your game.”

Brown, however, countered that claim by asking if it would surprise Fitzgerald to learn that the “manipulated” copy of the phone records in question “was the only version of that document Christina Gutierrez had”.

“I would be shocked,” Fitzgerald responded.

“It would be shocking, wouldn’t it?” Brown rejoined and went on to suggest that if Fitzgerald, one of the foremost cell tower analysts in the country, couldn’t understand the document, there would be no way that Gutierrez could have.

That line of questioning revolved around the use of cellphone records to determine location, one of the issues that allowed a judge to reopen Syed’s case, made famous by the podcast Serial. The defense argued that Christina Gutierrez, Syed’s attorney at the time, had not properly cross-examined the state’s expert witness on cell tower location technology. Fitzgerald began his testimony on Friday by arguing that the cellphone expert in the 2000 trial had followed standard procedures that the FBI still follows today.

But according to Syed’s family, the most important moment on Friday may have come just before the court adjourned for the day when Syed’s lawyers introduced a final piece of what could prove to be decisive evidence regarding Gutierrez’s failure to contact alibi witnesses. Brown introduced an affidavit from Ja’uan Gordon, a friend of alibi witness Asia Chapman (then McClain) who, the prosecution suggested, told investigators in 1999 that Syed asked Chapman to write and predate one of the letters about the time they allegedly spent together in the library at the time Hae Min Lee was murdered.

“In my interview with police on 4/9/99 I was not suggesting that Adnan or anyone else did anything deceptive,” the affidavit read. “I recall telling police that Adnan talked about asking Asia to write a character letter … I have no knowledge of Adnan asking Asia to write anything fraudulent, or with intentions of misrepresenting anything to the court. I was not in any way suggesting that in my interview with police.”

The post-conviction hearing was granted in part because Gutierrez never investigated McClain’s claims that she was with Syed at the library. Syed’s current defense team claims Gutierrez provided ineffective counsel due to health and financial problems. She was disbarred the year after Syed’s conviction and subsequently died. The judge on Monday declined to allow her disbarment records into evidence.

Much of the state’s case on which Syed’s conviction should stand rests on deputy attorney general Thiru Vignarajah’s claims that Gutierrez provided adequate, if not excellent, counsel, and that she had good reasons not to contact Chapman.

As Vignarajah cross-examined David Irwin, a defense expert witness whose testimony was interrupted to accommodate a state witness’s schedule last week, his queries continued to revolve around a statement found in police files that indicated that Syed may have asked McClain to write the letter. Syed’s defense later displayed on the courtroom screen the police statement, which claimed that Syed “wrote a letter to a girl to type up w/ his address on it but she got it wrong”. Later on the page someone had marked “Asia?”

Though that note was not in Gutierrez’s files, the state argued that the “open file” policy maintained by the state attorney’s office and the police department towards defense attorneys meant that Gutierrez could have seen it and steered her strategy in another direction.

Brown would not comment on the affidavit, but Syed’s family felt that the affidavit of Gordon was a powerful defense against this line of argument.

“If you listen to Thiru … he kept on questioning Asia telling her ‘What if Ja’uan said this. He was trying to twist what Ja’uan said and bam – we have an affidavit from Ja’uan,” said Yusef Syed, Adnan’s brother. “All four days are like that – the state will try to say something, they get smacked right in the face.”

Both sides are scheduled to offer closing arguments tomorrow – though there is still a chance that the defense will offer more rebuttal evidence – if the court is open amid forecasts of snow.