On Monday, prosecutors released more details from their investigation, and say that Harris may have sent lurid text messages to as many as six different women while he worked June 18 as his son slowly died. Previously, they said Harris researched hot-car deaths online in the weeks before the boy's death.
He has been charged with felony murder and second-degree child cruelty, and is being held without bail. He has pleaded not guilty.
If Harris is found to have orchestrated his son's death, this case would be an anomaly. There are an average of 38 vehicular heatstroke deaths per year in the United States, but the number of cases that may involve criminal intent are exceedingly rare. Most don't even involve recklessness on the part of parents or caregivers.
Instead, many of these deaths occur under the most mundane of circumstances: a sleep-deprived parent forgets a sleeping child in the rear seats, a child climbs into a car without knowledge of others, a parent steps away expecting to be gone for a minute and gets distracted for a longer period of time.
So far in 2014, there have been 15 vehicular heatstroke deaths, according to Kids and Cars, a nonprofit advocacy group that tracks the deaths of children in vehicle-related incidents. Two have occurred since Cooper Harris died.
Last week, a two-year-old boy in Buford, South Carolina, woke up from a nap and locked himself in the family car without a parent knowing he was gone. He died Sunday. That same day, a two-year-old girl in El Paso, Texas, was found dead in a hot car.
Regardless of intent, authorities often bring some sort of charges against parents responsible for care of the child. An Associated Press analysis of more than 310 fatal incidents conducted in 2007 found that charges are filed in half of all cases, and that the charges and sentences can vary widely based on where the death occurred and whether the mother, father or another caregiver was responsible for the child.
Perhaps not surprisingly, many of the deaths have occurred in southern states. Texas and South Carolina have each suffered three such deaths. But they've also occurred in places like Illinois, New York and Georgia. Janette Fennell, president and founder of Kids and Cars, says that underscores that these vehicular heatstroke accidents can happen anywhere – and to anyone. In years of examining these deaths, she says she's talked with teachers, pediatricians, dentists, postal clerks, police officers, nurses and an assistant principal, among others, who have lost children in these types of accidents.
"Absolutely the worst thing a parent can do is to think that this could never happen to them or their family," she said.
In more than half the cases examined by Kids and Cars since 1991, parents unknowingly left children in a vehicle. Often a small disruption to a routine, such as a phone call or a stop for food, can lead a parent or caregiver to make a scheduled daycare stop. In 31.5 percent of the cases, children got into the vehicle on their own. In 11.9 percent of the cases, a parent knowingly left a child in the vehicle, and in 1.8 percent of cases, the circumstances are unknown.
Several companies offer devices that ostensibly alert parents to children in the back seat once a car's engine is turned off. But a first-of-its-kind study conducted by the Children's Hospital Of Philadelphia in 2012 found many of the devices were "inconsistent and unreliable."
Safety advocates tell parents to keep a briefcase or cell phone in the backseat – something that triggers an automatic look at the rear when arriving at a destination. Fennell has another suggestion: A more-reliable technology that's built into the car itself.
"The auto industry recognizes we're human and not perfect, so if you leave your keys in the ignition, you get a warning," she said. "If your gas is low, you get a warning. If you don't buckle your seatbelt, you get a warning. If you leave your headlights on, you get a warning. So the question is, 'Who decided it's more important not to have a dead battery instead of a dead baby?' I don't want that to sound harsh, but that's reality."
Pete Bigelow is an associate editor at AOL Autos. He can be reached via email at firstname.lastname@example.org and followed on Twitter @PeterCBigelow.