CPS takes daughter from custodial mom and gives to absent non-custodial father

what happens during and after this?
the cps lets the stepdad's parents sign a voluntary caregiver agreement and she's still on it but they changed their mind 3 days later and called the mom and said to bring the daughter to the office in a neutral place because the bio dad is coming to get her. at the office, the mom wasn't asked to sign anything. and he hasn't been involved in his daughter life for about 5 years by his own choice, until the cps call. he now doesn't let the mom speak to the daughter or see her, but she has visitation rights. the mom is the non-offending parent in the cps situation. the stepdad is in jail.
the voluntary agreement that the daughter is still supposed to be with the stepdad's parents is still in effect says until next month.
Can the absent father really have control and take the daughter away for good, without the custodial mom having any say in it or signing anything?
the daughter doesn't know who he even is and hasn't all this time and she cried when she was leaving the mom.