This may be difficult to clarify.
Not difficult to clarify at all.
If the defendant, who happens to be 20, is living at home and claimed as a dependent; am I able to sue and obtain a judgement under home owners insurance as long as he is not convicted?
You can certain sue and probably win a judgment.
But (whether he's convicted or not) it isn't likely to be paid for under the family homeowner policy.
Homeowners liability coverage contains the following exclusion:
Expected Or Intended Injury
"Bodily injury" or "property damage" which is expected or intended by an "insured" even if the resulting "bodily injury" or "property damage":
a. Is of a different kind, quality or degree than initially expected or intended; or
b. Is sustained by a different person, entity, real or personal property, than initially expected or intended.
It's likely that the homeowner insurance company will just deny coverage and leave the 20 year old on his own.
However, judgments in MA are enforceable for 20 years, so he will have it hanging over his head for a long, long time and some day he might have to face up to it, or file bankruptcy and dispose of the debt.