I need to file a report on a neighbor who is her mother's caregiver. How can I remain anonymous?

I need to file a report on a neighbor who is her mother's caregiver,she smokes drugs and has an abusive live in boyfriend.This is in Las Vegas, NV and the caregiver is often seen smoking drugs with an adult female family member, a niece and you can smell an odor coming from her garage at all times of the night. The boyfriend is an ex con and used to be a boxer . I have witnessed him cussing at the caregiver's mother, who is disabled and barely gets out. I do not want to get too involved, so can I remain annonymous? Also, the caregiver has a pre teen niece that was caught smoking drugs 2 months ago. I believe 13 years of age.