GRAND RAPIDS, Mich. — The lead detective tasked with investigating the death of a 9-month-old northern Kent County girl said he had to leave the room after seeing her filthy and emaciated body. 

"I've seen a lot of things in my career... I knew that I was going to see a dead child," said former Kent County Sheriff's detective Jason Russo, during his testimony Thursday. "That was not what I expected based on the initial interviews with the parents. It was indescribable. I can't forget it to this day."

Russo became choked up on Jan. 23 as the prosecutor asked him about his investigation into the August 2018 death of Mary Welch. The medical examiner concluded the baby's cause of death was dehydration and malnutrition due to neglect. 

Seth Welch and Tatiana Fusari, Mary Welch's parents, are both facing charges of felony murder and first degree child abuse in their daughter's death. Seth Welch's trial began Wednesday. Fusari's trial is scheduled for next month. 

Jurors heard recordings of interviews between Seth Welch and police. Welch can be heard telling sometimes conflicting stories about his daughter, but he maintains that she ate constantly. By the time she died, Mary Welch weighed just over a pound more than she did at birth. 

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Tamara Flowers, a woman who briefly stayed at Welch's Solon Township home in July of 2018, also testified Thursday. She said she wanted to call child protective services after seeing the baby's sunken in cheeks and the way she was treated by Seth Welch. She ultimately chose not to call, and a month later she saw the reports of Mary Welch's death. 

"I felt like if I would've called CPS when I said I was...that baby would've still been alive and she could've had a chance," Flowers said with tears rolling down her cheeks. 

A member of the victim services unit at the Kent County Sheriff's Department testified that when he arrived on scene to aid the family, Seth Welch acted completely unfazed. He said Seth Welch replied 'life goes on,' when asked how he was handling his daughter's death. 

"I've seen a lot of things in my different careers," said Leonard Misner, a former EMT and Marine. "This is one that I will never for the rest of my life forget. It was in my opinion the coldest most detached response from anyone I've ever seen." 

The trial continues Friday and is expected to last into next week. 

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