Patricia Stallings

But then, there are other cases that seem clear-cut and solved at first, but turn out to be far more complicated than anyone could imagine.

September 1989, Patricia Stallings was standing in front of her house in Jefferson County, Missouri, when officers placed her under arrest.

The charge? Murdering her infant son, Ryan.

Just three months earlier, Patricia and her husband, David Stallings, had brought their three-month-old baby to the hospital.

Investigators also pointed to a bottle of antifreeze found at the Stallings' home.

According to the prosecution, nothing else could explain the ethylene glycol detected in Ryan's blood.

After 10 hours of deliberations, the jury found Patricia Stallings guilty of first-degree murder.

She was sentenced to life without the possibility of parole.