That's an excellent question, one that touches the central problem I have encountered in debating those who believe Amanda and Raffaele are guilty.
These debating partners, for the most part, lack even the most rudimentary understanding of criminal investigations, police procedures, and the circumstances that give rise to wrongful convictions. But worse that that - they don't think they need to learn. They assume that common sense is an adequate basis for assessing how innocent vs. guilty suspects behave, whether innocent people falsely incriminate themselves when they are under pressure, etc.
I have posted this essay before, but this seems like a good time to post it again:
How do ordinary, innocent people behave when they stumble onto a crime scene? Following is an example from a murder that took place in Washington State.
Jerry Heimann was a 64-year-old man in Everett, Washington. He lived with his mother, who had Alzheimer's disease, as well as his mother's caregiver and her children, who lived in the basement. On April 13, 2001, the caregiver persuaded some friends of her teenage daughter to kill Jerry so they could loot his bank account. They stabbed and bludgeoned him to death, threw his body in the woods, loaded his furniture into a rented truck, and vacated the house after cleaning up the kitchen where they had attacked him. They left the old lady to fend for herself.
Jerry had prior reason to doubt the goodwill of his mother's caregiver. Just a week or two earlier, she had stolen $1,800 from him by forging a check. Jerry called his son Greg and told him about this, and Greg advised him to fire the caregiver, but Jerry did not do so. Nor did he call the police.
A few days after the murder, Greg and his wife flew in for a visit they had been planning for months. Jerry had said he would meet them at the airport, and they were expecting him. They waited for three hours before taking a cab to Jerry's house.
When they got there, the place was dark and no one seemed to be home. They looked around and managed to get in through a window. The first thing they noticed was that most of the furniture was gone. Then they found Jerry's mother, who was sitting in her wheelchair chewing on a piece of paper. She was hungry and dehydrated, and she had soiled her diapers. They got her cleaned up, fed, and put to bed. Then they got some groceries and prepared a meal for themselves in the kitchen. After dinner, they decided to call around to find out if anyone knew where he was. That was when they noticed that all the phones in the house had been unplugged and the answering machine had been disconnected.
Numerous phone calls produced no report of anyone having seen Jerry in the past week. By then it was well into the evening and the couple was tired after a long day, so they went to bed. Greg awoke at 3 a.m. and couldn't get back to sleep, so he went downstairs to the kitchen. While he was sipping a cup of coffee, he suddenly noticed blood on the back of the chair next to him. In fact, there was quite a bit of blood spattered on it. Casting his eyes around the room, he noticed for the first time that there was blood on the walls, too. And there was blood running down the side of a trash can in the kitchen.
That was when Greg decided he should call the police... but, he didn't actually do so.
Instead he sat around until about 7:00 am, when he received a phone call from his mother, who lived in the area. She asked him to wait for her to get there before calling the police. So he did.
Shortly after 8:00 am, someone knocked on the door. It was a man from a government agency, Adult Protective Services. He had come to investigate an anonymous tip that the caregiver intended to harm Jerry Heimann. Greg described the situation to this individual, who immediately used his cell phone to call the police.
Why didn't Greg call the cops the minute he arrived at his father's house and found the furniture gone and the old lady in a state of neglect? Isn't that what any normal person would have done?
How could Greg and his wife prepare and eat dinner in a kitchen where there was blood spatter on the walls and furniture without even noticing it? And why, when he noticed the blood spatter, didn't Greg immediately call the police?
Anyone who sets out to analyze whether certain types of behavior are indicative of guilt should start by reading some crime stories to get a sense of what is "normal." The fact is that "normal" behavior is all over the map and very often seems ridiculously naive or clueless when viewed with the benefit of hindsight.
My source for the above is Mom said kill, a book by Burl Barer about the Heimann murder.