This statement appears to be false, according to the linked DOJ report below (despite the claims made by the comment).

The report indicates violence committed by strangers is 2-3 times that of violence committed by known individuals.

The linked report seems to indicate, in every year of every chart, "stranger violence" to be 2-3 times that of "domestic violence" (depending on the specific measurement).

Perhaps you were citing reporting percentages?

Domestic Violence is defined in the report as "includ[ing] the subset of violent victimizations that were committed by current or former intimate partners or family members, spouses, boyfriends, or girlfriends."

Stranger Violence is not defined in the report, but seems fairly clear non-the-less.

The report also states homicide statistics are not included in the figures.