A Nicaraguan man is in custody accused of sexually assaulting a child and human trafficking in Fond du Lac County. Early Sunday morning the Sheriff’s Office received a call from a town of Oakfield resident who said a child showed up at his door for help. The girl said she fled from a vehicle where a man had bound and blindfolded her and was attempting to assault her. Officers learned the identity of the suspect and Monday evening the police SWAT team arrested the man at a Marquette Street residence in the city of Fond du Lac. It is alleged the man paid the victim’s mother to spend time alone with the victim. Investigators say he entered the United States illegally from Mexico three years ago. The mother also faces charges related to the case. The 12 year old victim and her siblings have been placed in protective custody.