PLEASE HELP!!! HOW DOES THE CRIMINAL JUSTICE SYSTEM IN NIGERIA WORK?

Hello, trust you are doing well by God's grace?  Don't bother trying to find out how I am doing because I don't think I'm fine at all!!! It's 5.18am here and I haven't slept at all ... just here all night, shinning my eyes and trying to work on my final MSc project/dissertation but I'M STUCK!!! 

Somebody please help me oooo! Can you kindly tell me in simple terms how the criminal justice system in Nigeria works? Is the federal law and Criminal Code Acts applicable in all states? Where does that Sharia law thingy come in? Is Sharia the same as the penal code? And which one is criminal procedure code/law/acts  again? *confused look*  

While I was researching, I came across this "The criminal justice system in Nigeria starts to run with the commission of a crime and straddles subsequent interventions by agencies of the system such as arrest, arraignment, trial, sentencing and punishment of the offender. Given that the country operates under a federal arrangement, the processes are governed by an array of federal and state legislations. The Criminal Code Act and the Criminal Procedure Act (CPA) as well as the Criminal Code Laws and Criminal Procedure Laws (CPLs) apply in the Southern States of Nigeria except Lagos State while the Penal Code (Federal Provisions) Act and the Criminal  Procedure Code apply as federal legislation in the Federal Capital Territory of Abuja and the Penal Code Laws of the State and Criminal Procedure Codes apply as state legislation the Northern states of the country." -Anyebe, 1990       CAN ANY YOU PLEASE EXPLAIN THIS PARAGRAPH OR BETTER STILL JUST HELP ME RE-WRITE THE PARAGRAPH IN A WAY ANY 10 YEARS OLD WHO HAS NEVER BEEN TO NIGERIA WILL UNDERSTAND?.  Ese/Daalu/Na gode/Thank you  

Finally my research topic is "Effect of sexual Abuse on Nigerian Women's health". If you know any Nigeria laws/acts against sexual violence, sexual abuse, harassment or rape etc please kindly state them below or direct me to where I can find them. 

*Thinking out loud*  I know I didn't make a mistake using Nigeria as a case study and I'm very confident it isn't a crime to carry out a research that could help me make impacts in my home country someday !!! As much as I love this research topic, finding necessary information and relevant data on serious issues affecting Nigeria is really FRUSTRATING! It's either nobody responds to your emails or the silly numbers they put on those official websites just never go through... Omo I don tire but I no say one day one day Naija go better! AMEN.

Thanks in advance for your help,

God bless you.