I've also hesitated to weigh in as this case brings back very sad and traumatic memories for me. I've related this story before but it probably bears repeating, as a cautionary tale, on this thread.
We adopted a 3 year old little girl from Haiti in the late 80s. We were told that her mother had died soon after her birth and that she'd grown up in a Christian orphanage with excellent care. She was quite the favorite of a nurse who visited the orphanages and she had successfully treated the child's TB. We traveled to Haiti (during a coup, no less) in December 1989 and spent a week with our new daughter and seeing Port au Prince. Never have I been so taken by a country. The people were gracious and kind and welcoming even though the poverty was staggering. Our daughter was adorable and seemed hale and hearty. She was very quiet but we figured that she was just frightened and shy. We already had three birth children and two internationally adopted children so we had some experience with the trauma of transition. After a week, we brought her home. Things did not go well.
Our little girl did not speak. She had horrific night terrors, acting out some strange behaviors. She bit and head butted. She hurt the animals. She hurt herself. She rocked and seemed to be in her own little world until she'd hurt herself or someone else and then she would giggle uncontrollably. She constantly tried to insert toys and other objects, ie utensils, into her vagina. She put things into her mouth which gagged her. We sought help.
The therapist spent some time with her and said that this child had most certainly been seriously abused. We were crestfallen as this had not been disclosed and we had no experience at the time with seriously traumatized children. Our family does not easily give up, however. Adoption was permanent, in our eyes. We kept trying, even though her rages and violent behavior escalated.
One night, at the age of 5, we woke to horrific screams. At first we thought that she was having another night terror. These were common. She would stand in the middle of the room spinning, shrieking and mumbling for hours. Her eyes were open but blank and one ankle, her left, seemed to be pinned to the floor, even though she was free to move. We'd tried everything--warm baths, food, taking her outside, rocking her, music. Doctors tested her for seizures and she was healthy. Nothing worked. They lasted 3-4 hours until she would fall into a stupor and sleep for 12-15 hours straight.
But this night, it was not her screams. They were the screams of our 6 year old daughter. She'd been stabbed in her sleep. Our 5 year old had crawled up into a closet and found my very sharp sewing scissors. She proceeded to cut the girls' dresses which were hanging in the closet, in half. She also poked holes in the bodices of the dresses and tops. She then went to the older girls' room where our 6 and 8 year old daughters slept and attacked the 6 year old through the bedclothes. When we came running, there she was crouched in the corner of the room giggling and playing with the scissors, trying to cut herself. My husband went to her and I went to the 6 year old, who was bleeding. Thankfully, the slices were not terribly serious but she did get stabbed and sliced in 6 places, including the back of her neck. It took my husband, a 200 lb man, a good 15 minutes to get the scissors away from our daughter. He ended up playing a game with her and she finally threw them towards him. He then swept her up and we sat up with her the entire night as she head-butted the walls, bit herself and pulled at her genitals. It was, bar none, the most horrific night of our lives.
The following day, we took her to the therapist who was mandated to make a report. The police had no idea what to do nor did we. We were exhausted, though, and it was clear that we could no longer parent this child. DHS helped us go to court and we asked the judge to dissolve the adoption so that she could be placed in a treatment home with no children. The day she left, she never turned around to look at us. The lovely doll which I sent with her was destroyed in the social worker's car. She also ripped her clothes off.
We learned later that she'd been placed with a couple who had no children. But they had a dog. She killed the dog. When it was examined, it was found to have needles inserted under its skin, especially around her genitalia. Our little girl was then sent to a specialized residential facility. I'll never forget receiving a detailed report about a year later concerning her. There on the forms was a diagnosis, "homicidal tendencies". I was ruined. Homicidal at age five?
Two years passed and our family began to heal. We ended up having 7 children placed with us for adoption within an 18 months period. Many were tough kids but nothing like the challenges presented by our one little girl. One day, out of the blue, we were contacted by a missionary who'd just returned from Haiti. He'd had a falling out with the orphanage director where our little girl had been. He told us her real story.
She'd been "sold" to a Haitian minister's family who used her as a scapegoat. She was locked in a filthy, bug infested closet and taken out only to be raped for her first 2 1/2 years, before being sent to the orphanage which chose not to disclose this into to us. He'd been told that one of the young men in the family used a fork to penetrate her and that she was used in frequent voodoo rituals. When she was allowed to be out of the closet, her foot had been staked to the ground...her left foot. It all suddenly made sense.
May God watch over that child. I have no idea where she is. But I know that she lived through hell. I hope she's found some peace.
The bottom line is that trauma or faulty brain chemistry can cause very young children to do the unthinkable.