This cannot be an ad-hoc "militia." It must be a formal, legally recognized entity to provide structure and liability protection.
1Form a Legal Entity
Create a formal neighborhood watch program. This is typically done in partnership with your local law enforcement agency. Many police departments have dedicated community outreach officers who can help you establish an official, recognized watch.
2Liability Insurance
If members will be performing any patrol functions (even just observing), the group should be insured. This protects members and the community from lawsuits in case of an incident. An attorney can advise on the necessary insurance products.
3Non-Profit Status (Optional but Advised)
Consider forming a 501(c)(4) social welfare organization. This provides a structure for fundraising, spending, and operations while emphasizing the community benefit purpose. An attorney specializing in non-profit and firearms law is essential for this.