Protesters marched on City Hall Thursday to demand transparency in the police-involved shooting death of Saheed Vassell in Crown Heights earlier this month.

Vassell, a 34-year-old mentally ill man, was brandishing a metal pipe like a gun, prompting multiple 911 calls, police say.

When officers arrived, investigators say he aimed the object at them, and they shot and killed him. The NYPD released surveillance video from various angles showing him waving it around, even shoving it in the face of someone walking with a child at one point.

But in those videos, it's hard to see the actual shooting. None of the officers who opened fire were wearing body cameras. 

Police say they discovered the object was a pipe with a knob at the end after the shooting.

Protesters say they want a full investigation from the mayor's office and to know the names of the officers involved in the shooting. They say the released video unfairly depicts Vassell as a menace.

Meanwhile, the state's attorney general has opened an investigation into Vassell's death.