DETROIT – A hearing to determine whether new evidence warrants a new trial for Mario Willis continued on Wednesday, with prosecutors challenging defense expert testimony.
Willis, who was convicted in a 2008 fatal fire that killed Detroit firefighter Walter Harris, returned to court for the sixth day of proceedings that began in December.
His defense team is seeking to overturn his conviction based on new evidence that they say challenges the original case.
The prosecution spent hours on Jan. 7, 2026, cross-examining defense expert Marc Fennell, who previously testified that the original fire investigation was flawed.
Prosecutors meticulously questioned Fennell about his 38-page report and his conclusion that the fire’s cause should be classified as “undetermined” rather than arson.
During intense questioning, prosecutors challenged Fennell’s methodology and sources.
“Where do you explain all the things you just told us – that you don’t have photos, you doubt whether they were taken, you don’t trust that he had a clearly defined origin?” the prosecutor asked. “Where in these 38 pages do you do that?”
Fennell raised concerns about the lack of photographic evidence.
“If he says there’s an actual point of origin that’s clearly defined, where are those photographs?” Fennell said.
The December proceedings included testimony from key witness Darian Dove, a handyman who testified he was paid to start the fire.
Under questioning, Dove said Willis had instructed him to start the fire, though he also admitted to being a pathological liar.
Original fire investigator Capt. Rance Dixon also testified in December, standing by his initial report.
The hearing is scheduled to continue on Thursday (Jan. 8) with further cross-examination of Fennell.
Additional witnesses, including attorneys from the original trial, may testify next week.