No, it will not be a lost cause if you want your brother criminally prosecuted for the crimes. This may or may not get your property back, it will probably harm the relationship between the two of you.
Every crime has its elements. Assuming your brother does not have permission to take the items and has not returned them, he may be guilty of various crimes, including theft. In Nevada, theft is addressed in NRS 205.0832 (Actions which constitute theft), which reads:
1. Except as otherwise provided in subsection 2, a person commits theft if, without lawful authority, the person knowingly:
(a) Controls any property of another person with the intent to deprive that person of the property.
(b) Converts, makes an unauthorized transfer of an interest in, or without authorization controls any property of another person, or uses the services or property of another person entrusted to him or her or placed in his or her possession for a limited, authorized period of determined or prescribed duration or for a limited use.
(c) Obtains real, personal or intangible property or the services of another person by a material misrepresentation with intent to deprive that person of the property or services. As used in this paragraph, “material misrepresentation” means the use of any pretense, or the making of any promise, representation or statement of present, past or future fact which is fraudulent and which, when used or made, is instrumental in causing the wrongful control or transfer of property or services. The pretense may be verbal or it may be a physical act.
(d) Comes into control of lost, mislaid or misdelivered property of another person under circumstances providing means of inquiry as to the true owner and appropriates that property to his or her own use or that of another person without reasonable efforts to notify the true owner.
(e) Controls property of another person knowing or having reason to know that the property was stolen.
(f) Obtains services or parts, products or other items related to such services which the person knows are available only for compensation without paying or agreeing to pay compensation or diverts the services of another person to his or her own benefit or that of another person without lawful authority to do so.
(g) Takes, destroys, conceals or disposes of property in which another person has a security interest, with intent to defraud that person.
(h) Commits any act that is declared to be theft by a specific statute.
(i) Draws or passes a check, and in exchange obtains property or services, if the person knows that the check will not be paid when presented.
(j) Obtains gasoline or other fuel or automotive products which are available only for compensation without paying or agreeing to pay compensation.
2. A person who commits an act that is prohibited by subsection 1 which involves the repair of a vehicle has not committed theft unless, before the repair was made, the person received a written estimate of the cost of the repair.
Hope this helps.
/s Donald Kudler