I Need Help? My Husband Needs to Get Custody of His Son but Doesn’t Have Money for Legal Representation?

My husband has a child from a previous relationship. His son’s mother and him were never married. The mother of the child has a HORRIBLE crystal meth addiction. The mother got a charge for burglary but then dropped dirty to crystal meth 3 times at a probation meeting a was sentenced to prision. The child lived with us while she was in prision. My husband was in the middle of getting custody and had already filed for child support when she got out of prision and took him out of our babysitters house while we were at work? She has now filed for child support against him and he is paying her 450 a month child support. She takes that money and buys meth and then 2 days after she gets her child support she calls asking him to buy diapers. The child has a burn on his leg as a result of a meth pipe. She will not let my my husband see him at all unless she is present. Everytime we see his son he has not had a bath in days. We have called the abuse hotline twice. How do we get custody of him?
I live in Kansas City MIssouri, The day the women got out of prision she called the police and said that her child was in that home and wasn’t supposed to be. The police took his son out of that home and gave him to her. When my husband got off work he called the police and they told him that they don’t interfere with child custody cases. So we called internal affairs with the police department and got the 2 police officers suspended from the force. This women walked out on my husband when she was 2 months pregnant and said she was getting an abortion then called my husband when their son was 2 months old to inform him he had a son. She smoked crystal meth until she was 8 months pregnant and was even in rehab for it while she was pregnant. as soon as she had their son she was right back at it. She is so out there on meth that she thinks her teeth are meth and smokes them. My husband and I have never done drugs. We live in a safe and VERY clean home. She lives at home with her mom.
She is 26 with 4 kids and the oldest being 12. She stays at her mom’s house with all four of her kids. Her house is so dirty and disgusting we have turned it in because their is black mold in the house. The whole reason that she is angry and not letting my husband see their son on his own is because when she was in prison we took him to live with us and she expected us to let him stay there with her mom. And only come see him every weekend. That’s not going to happen. Any parent that cares about their kid wouldn’t let them live in that kind of enviroment. Like I said before We live in a very clean stable home. My husband has never had a criminal record. He has only had one speeding ticket. I need help with this situation it is so confusing. I could keep going on with all the things this mother does but it would take days
And to add one thing she does not and WILL not work. She collects welfare which makes me really upset because my husband and I have to work to support our children but she don’t. My husband and I have a son together and I have a litlle girl from a previous relationship. She uses my tax dollors and the child support to buy drugs and then turns right around and says he needs something. She always has her hair and nails done and dresses fairly nice but their son and all her other kids haven’t had a bath. She has name brand clothes while her kids wear shoes from walmart. As a parent don’t you put your children first?