16 The trouble they cause recoils on them; their violence comes down on their own heads.

Read Psalm 7:16 Using Other Translations

His mischief shall return upon his own head, and his violent dealing shall come down upon his own pate.
His mischief returns upon his own head, and on his own skull his violence descends.
The trouble they make for others backfires on them. The violence they plan falls on their own heads.