Brutality (noun)

1. The quality or state of being brutal; cruel or savage behaviour.
2. Unnecessary and excessive violence or force.

Origin:

From brutal + -ity, first recorded in the 17th century.

Examples:

1. The police were accused of brutality.
2. The soldiers were accused of committing brutalities.
3. The brutality of the war was shocking.
4. The brutality of the crime was unprecedented.
5. The brutality of the dictator's regime was well known.