The incident has gained national attention because it was captured on Facebook Live.
A woman presumed to be a family member (likely a cousin), Dekenia Thats'my-Attitude Mcneal, also went off on people sharing the video on Holmes' shooting.
The other man inside the vehicle tells Holmes to calm down as the weapon had no ammo in it.
He then asks "Where you from again?" before the woman points the gun at him.
Houston police say this happened at a gas station on Almeda Road around 2:30 Sunday morning.
Holmes was nervous when Damper picked up the gun.
Footage seen on social media does not show the moment Holmes was gunned down but does show him slumped over and covered in blood.
Damper allegedly tried to remove gun residue from her hands after the shooting, which police are preliminarily investigating as accidental.
Following the shooting incident, Click2Houston reported Damper and Coleman fleeing the vehicle, leaving Holmes bleeding out in the front passenger seat.
Meanwhile, the woman who shot Holmes has only been charged with evidence tampering.
The victim, who has not been named by cops, was rushed to hospital where he is now on life support.
Damper reportedly told police she believed the gun was unloaded.
A horrific video of a Texas man getting shot in the head has gone viral.
Authorities said a grand jury will decided if any additional charges should be filed.