The article is here:
http://newsok.com/article/5536089
One of a couple take-aways in the article:
" ... and his colleagues on the tactical team were discussing the day before they ended Vance's life.
“As we're talking around this deal, that was one of the things we were talking about,” Costanza said as he patrolled Okmulgee on a crisp January afternoon. “I know I've got a double murderer in front of me who at that time had already shot two cops and an innocent civilian at a carjacking, is it reasonable to believe that if I let him get away that he's going to leave and hurt more people?”
I tried searching a couple ways but I did not find anything on the initial fight.