I sublet my home to a friend, and she has brought her boyfriend to live in. Neither of them are actually tenants, since neither are on the lease. Lately, after voicing my concerns about the boyfriend, I actually feel afraid of this person. She and I have fought about having him leave, and she has threatened me. Since he doesn't have tenant's rights, can I have police remove him since I feel afraid of him?

If SHE threatened you... call the police for a start. No tenant law in the country allows a tenant to threaten you.

Does your lease with her prevent a sublet? The actual wording of the lease has importance in this case. In the past I have had leases that actually prevented it... most of them in fact did... and a rental property my family used to own had it worded into the lease as well.

"Neither of them are actually tenants, since neither are on the lease" oh yes they are. When you sublet you created a tenant status with her. Your verbal agreement is her lease. If you did not say from the start that she could not have the BF live with her then she became his landlord. If your agreement is month to month just start the eviction process, they both have tenants rights and are residents. Where do you live?

Agree, they are indeed tenants, they are YOUR tenants. You are a tenant of the owner of the property.

You will need to evict.

Now another issue, are you allowed in your lease to sub rent your appointment. If you don't have permission to rent to her, you have an "illegal rental" and this can cause you issue with them even being able to sue you for money back they have paid you.

So please come back and give us a lot more details,

... If you did not say from the start that she could not have the BF live with her then she became his landlord....

I disagree with this part. The BF's status as a tenant doesn't depend upon the verbal rental agreement between the OP and the GF.