Your friend is facing some pretty serious charges. Second degree kidnapping can range from a Felony 2 to a felony 4 and can also be a crime of violence (COV) under certain specific circumstances. If a COV then it has to be so charged separatley which the DA can do much later when the matter is set for trial. COV entails manadatory sentence and if convicted he will also have to complete minmum manadatory sentece in DOC before being eligible ffor parole. Manadatory Parole for F2 and F 3 convictions is 5 years for F 4 it is 3 years.
Sentences can range for F 2 from 4 to 48 years; for F 3 from 2 to 32 years and F 4 from 1 to 16. These are possible sentences and does not mean that is what yoiur friend will get if convicted.
It is best to consult with a criminal defense lawyer.
Bail is upto to the Judge based on a lot of factors which a criminal defense lawyer can place before the Judge for consideration.
Your question was posted about 1 day ago. You are asking how long they are holding him for? Due to the seriousness of the crime and that it was a crime against a person, they will want to bring him before a Judge or Magistrate to enter a criminal restraining order (18-1-1001 Restraining Order) prior to setting bail. That says that he can have no contact with the victim or witnesses in this case. The Judge or Magistrate will then set bail. Under the statute there are very limited instances in Colorado where there can be "no bond". They will bring him before the Court at the next court setting when they conduct Advisements.
A bond hearing will be conducted and based on your friends criminal history, history of any missed court dates, alleged facts of the case and class of felony the bond will be set. The "standard" bond on an Felony 2 in Colorado is $100,000 and for a Felony 4 is $5,000. The bond would probably be set in that range or at those amounts for the level of crime charged.