The sociology of homicide

It is certainly true that at present, the rate of violent offending is considerably higher among African-Americans in the U.S. than it is among white non-Hispanics. The rate among Latinos is somewhat higher but not nearly as much. (However, the disparity is not as great as your teevee would have you believe.   Also here.)This observation, however, is specific to time and place. As Darnell Hawkins wrote in Health Affairs some year back (Winter, 1993):

In the United States the social scientific efforts to provide "causes" for
antisocial conduct, including violence, were first found in studies of white
ethnic groups rather than nonwhite groups. High rates of crime and violence
were said to be evident among the waves of immigrants from Europe
to America from the mid-1800s to World War I.8 Although statistics for the
past are not always reliable or easily obtainable, some data suggest that the
Irish, Italians, Greeks, Jews, and other groups of recently arrived white
ethnics during this period had considerably higher rates of homicide, assault,
and other forms of violence than is found among them today.9
These and other "new" immigrant groups of the period, especially second
and third generations among them, had higher rates of crime and violence
than the more privileged and settled ethnic groups that preceded them.
Roger Lane found that certain white ethnic groups in nineteenth-century
Philadelphia had rates of interpersonal violence that closely resembled
those of blacks living in the city.10 During this same period, Ted Gurr
reported that injury and death due to interpersonal violence posed a significant
risk among many of the nation's immigrants as well as among its less
advantaged native population.11

Indeed, when I first moved to Boston in the early 1980s, South Boston was still a low-income Irish enclave. Southie had the highest rate of heroin use and one of the highest homicide rates of any neighborhood in Boston. That included gang violence led by the notorious Whitey Bulger. You have no doubt heard of the Sicilian Mafia and watched the Godfather and other movies featuring their extreme violent proclivities. Following the Civil War and for many decades thereafter, white southerners reigned terror on African Americans in their midst,  and of course you may have heard about white German Nazis murdering 11 million people.

There is  large body of work finding that if you account for the concentrated disadvantage of certain communities, the racial/ethnic gap in crime, including violent offending, largely disappears. Unfortunately I haven't been able to find any readily accessible lay explications of this literature, which is largely highly technical and hidden behind paywalls in academic journals, although you can get some taste of it at the link. I'll keep looking. Homicide rates also vary by region. Rates by non-Hispanic whites are higher in the South than elsewhere in the country, and the racial disparity is less.

I have found no evidence that being from a single parent family is an independent predictor of violent crime. However, single parenthood is definitely predicted by social disadvantage, and vice versa.

The point is that the sociology of violence is very complex, but it's not a question of minority "culture" and the relationship to ethnicity varies over time and place. However, scholars are certainly not afraid to discuss these issues and there is extensive literature and debate about them. Pointing out the existence of racial/ethnic disparities in violent crime is not racist; but attributing them essentially to race is.