Yanez fired seven bullets at Castile, hitting him five times, after ordering the school cafeteria supervisor to pull his vehicle over because of a broken brake light.
Steven Belton is president and CEO of Minneapolis Urban League.
Federal prosecutors said they are assessing the case to see if it warrants further review.
Hatchett also discussed the Philando Castile Relief Foundation, which she said has already "given out scholarships in his honor".
Bekuh Sibet is a 29-year-old waitress.
Castile: "I'm not pulling it out". The video doesn't show what happened inside the auto.
Yanez: "Don't pull it out!".
The footage, which appeared on CNN, shows Minnesota police officer, Jeronimo Yanez, speaking to Castile about his break lights, which he deemed un-roadworthy. After an exchange in which Castile says he's carrying a weapon, Yanez fires several rounds into the auto, killing Castile.
Sampsell-Jones says it is "understandable why the jury couldn't find him guilty beyond a reasonable doubt". Yanez replied saying, "OK". The St. Anthony Police Department later announced he would not return to the force.
The shooting on July 6 past year, in the Minneapolis suburb of Falcon Heights, gained widespread attention because Mr Castile's girlfriend, Diamond Reynolds, live-streamed its gruesome aftermath on Facebook. Yanez's partner is seen waiting slightly further away from the vehicle on the curb.
Although the dashcam footage was described repeatedly and was shown to jurors in the courtroom, it was not made public until now. It shows a wide view of the traffic stop and shooting.
Dashcam video from the fatal shooting of a black man by a Minnesota police officer was released by officials Tuesday, days after the officer was acquitted in the man's death.
This was one of the pieces of evidence used in the trial. Both Castile and girlfriend Diamond Reynolds in the backseat said he wasn't. After warning Castile multiple times not to pull out his gun, Yanez shot Castile. He had a permit for it. The clip's release comes just days after Yanez was cleared of second-degree manslaughter, a decision that was greeted by protests around the nation.