As the smoke clears from a mass shooting at the U.S. Army base in Fort Hood, Texas, Wednesday. What exactly happened is beginning to come to light. Here’s what we know:

  • Around 4:30 pm at Fort Hood, an active-duty soldier opened fire.

  • He reportedly had a recently-acquired .45 caliber semi-automatic handgun.

  • Four are dead, including the shooter. 16 are injured, three in critical condition.

  • A female military police officer engaged the shooter, at which time he took his own life.

  • Lt. Gen. Mark Milley, the commanding general at Fort Hood, called her actions “heroic.”

  • The shooter was reportedly 34-year-old Ivan Lopez.

  • Lopez is apparently an Iraq veteran.

  • He had behavior and psychiatric issues and was receiving psychiatric treatment for depression and anxiety.

  • We do not know a motive.

  • His weapon was not registered on base.

The shooting comes five years after an Army Maj. Nidal Hasan, opened fire on a predeployment facility on Fort Hood in the name of Islamic extremism. Hasan killed 13 and wounded dozens more. Last year, he was sentenced to death and is currently on death row in Fort Leavenworth in Kansas