My daughter's sociopath

2 years ago my daughter (a single mother) began dating a sociopath. Within a month of dating this person, He had moved in with her and her children. He did not have a job or a car. When we were introduced, he told me stories of being in Iran as a marine, and served 2 tours of duty. He also gave me a false last name. i felt very uncomfortable around him, and I'm sure he sensed this. My daughter started bringing the babys over more frequently, and on occasion the oldest (only 3 at the time) would cry and cling to me when i would bring him home. Within the same month, he also called the police on the father of the children when he came to visit them, telling police that he had hit him. The father did have a warrant for not paying traffic fines, and the sociopath knew this and had him arrested in front of his children. he stole money from my daughter so often that she eventually couldnt pay her rent. Within 6 months of dating her, my daughter contracted std, but was told by him that she must have had it for over a year when she was still with her ex, and subsequently gave it to him. by this time the police had been called twice for domestic disturbance.
The sociopath got a job on a boat which my daughter brought breakfast to, and found him with another woman. This is just the beginning! my daughter was kicked out of what would be the first many places they lived.
I found out finally after a year of prodding that he had 2 of his own children from 2 different mothers, which he is not allowed to see. he had many lies as to why he didnt see them.
Finally my daughter and her children came to live with me as they had nowhere to go. he started sneaking into my home at night. I caught him sleeping in my own car in my driveway. I told him I would call the police, and he started mocking me by jumping on and off the curb to the street and saying, "Go ahead, Im not on your property"I was very frightened of him at the time. My daughter seemed to have an excuse for everything he did, often
using post traumatic syndrome one of them. eventually she borrowed money to get a new place, which he immediately moved into. within 2 months I started noticing that the children were dirty and often only brought over in diapers. She was beginning to neglect them. I had them 3 to 4 times a week by this time.
Finally i went to talk to her neighbors, who informed me that the children were often on their own outside, and when questioned, would say "mommys sleeping" or "I dont have a daddy" The neighbors also said that they fought daily. This was 1 year ago! I picked up my grandchildren and they have been with me ever since. Her place was disgusting! not fit to live in.
My daughter has been brought here by the police with bruises, been fired from 5 jobs, as he shows up at every job and causes a scene. She no longer comes to family functions and sees the children maybe once or twice a month. She has become his victim.
The thing I dont understand is that she used to be a good mother. A kind and loving person. How could she choose this sociopath over her children. By the way, she also caught him with a hooker while she was sleeping in her own house! he also has a very bad gambling problem. This is just the tip of the iceburg of MANY horrible things he has done to my daughter and our family. I have almost completely cut off contact with her in order to keep the children away from her, because she will lie and bring the kids around him every time.
i have sent many articles and web sites depicting him to a T as a sociopath, and she knows he is, but chooses to support his horrible lifestyle. I am at my wits end. I wish there was something that someone could say to help her see what is happening. She is in complete denial. I am heart broken.
On a good note, The children are thriving with me and my husband. Their father has moved in with us and is working and taking very good care of them while he gets back on his feet. We have all been victimized by this sociopath. What can I do? Tweet