ROCHESTER, N.Y. -- While many questions still remain about the incident that ended in the death of Richard Gregory Davis, 50, police said on Monday that cell phone video could give them some answers.

“We have obtained at least one cell phone video from a cooperative witness which does show a small portion of the incident,” Rochester Police Chief Michael Ciminelli said. “We have also located a home security camera video which does have some view of the vehicle on it. We’re still trying to analyze now what time the vehicle is portrayed in that.”

On Sunday morning, police say Davis did not obey their orders to stop his truck after a number of hit-and-run crashes on Tremont Street. Once out of the truck, they say he continued toward officers with his fists clenched even after they demanded he stop.

Police say six officers were involved in the incident and the one who used the taser, Officer Thomas Frye, is an eight-year veteran and Taser certified. He is also on the response team for emotionally disturbed persons.

Rochester Police Officer Dan Carlson, who is also the master taser instructor, explained when they typically use the taser.

“The type of behavior that we would reserve that for with the subject was displaying active fighting behavior, closing the distance aggressively, attacking, fighting stances,” Carlson said.

He also explained why another tactic like pepper spray may not have been used.

"Pepper spray would be something that we might deploy even a little bit earlier than the taser,” Carlson said. “The taser we can deploy it from a safer distance, than for instance punches.” 

Carlson also added weather is a factor in deciding what tactic to use as well.

Although Davis’ family said they the taser is what caused his death, noting he was 300 pounds and had a breathing problem, Carlson said being overweight can actually lessen the taser's effectiveness.

“Overweight by itself wouldn’t cause any particular extra concerns,” Carlson said.

Even so, Ciminelli said they are working to make arrangements to speak to the family directly.

“My message to them, as I said, is that they have our prayers, our sympathy and our thoughts, that this occurred,” Ciminelli said. “I can assure them that we will do a full, fair and thorough investigation to determine the facts and we will hold ourselves accountable for what we did and that’s my message to the family.”

Time Warner Cable News reached out the Medical Examiner’s Office for Davis’ cause of death, but it hasn’t responded.

Ciminelli said he is collecting the data on how many times the taser was deployed and the analytic data, as well as how often the taser has been used since they received them in 2003. Carlson said about half the force is taser trained and certified.

Ciminelli said Frye is on administrative duty while the investigation continues.