A man stabbed his sister and another man inside their northwest Miami-Dade County home, said police.
It happened in the 1600 block of NW 118th Street in Miami-Dade County.
An argument the man had with the two victims became heated, said police, and he then stabbed both victims.
The victims were taken to Jackson Memorial Hospital in critical condition. The man who stabbed them was arrested.
The names of the three were not immediately released.