Woman solved decades-long cold murder case after taking at-home DNA test and landed her grandmother in jail

A woman has put her grandmother in jail after solving a decades-long murder case with the help of a DNA test.

Michigan-based Jenna Rose was hoping to learn a little more about her family history when she unearthed the unthinkable.

"I've never made a video like this before. I keep stumbling over my words... this might take a few minutes to get through. It's a long story," the content creator said on her TikTok page (@__jennarose__).

"I've never met my grandmother, I didn't even know her name until I was 14 or 15 years old. This case was very popular in the town that I grew up in because it was so f***ed up.

"It was the Baby Garnet case... a lot of people have questions. I'm here to start talking about it."

Now, the Baby Garnet case was very well known in the area Jenna grew up in and involves the death of an infant believed to be around 36 to 42 weeks gestational age in June 1997.

The baby was found 'in a campground pit toilet at the Garnet Lake Campground in the Upper Peninsula’s Hudson Township' and investigators couldn't get to the bottom of it.

However, the case was reopened in 2017 when a Michigan State Police detective took a look at 'familial genetic genealogical tracing with the assistance of a private laboratory' possessing skeletal remains of Baby Garnet.

"They ended up finding out that it’s not a distant relative to my mom, but a direct relative, and the only other people it could have been was my mom’s mother," Jenna explained, as her DNA test came back as a 'relative' of the suspect.

"They kind of started doing their own investigation and figured out that’s who it was. So we were mind blown."

Her grandmother Nancy Gerwatowski, 60, of Wyoming, is set to stand trial for the cold-case murder of an infant discovered 27 years ago.

She is facing life behind bars after being charged with one count each of Open Murder, Involuntary Manslaughter, and Concealing the Death of an Individual.

"Mind you, I’ve never met this woman before. She is literally the f***ing person that they’ve been looking for, for 25 years. And it’s all because of a f***ing Ancestry DNA kit," she added.

"Thanks to the incredible efforts of investigators across three decades, we are finally able to pursue justice for Baby Garnet more than 25 years after her tragic death," said Michigan Attorney General Dana Nessel.

"In 1997, genetics testing was nowhere near as sophisticated as it is today, and I am grateful for the work of detectives and responders on-scene to preserve vital evidence in this matter.

"Prosecutors in my office are able to bring about this long-delayed criminal trial because of twenty-seven years of sound police work, scientific advancement, evidence preservation, and diligent state and local detectives who never gave up on justice for this infant victim."

A hearing is scheduled to take place on 12 December.

LADbible Group has contacted Michigan Department of Attorney General for further comment.