According to a statement from the Pine Bluff Police Department, police officers entered the home to find two victims who said that Isadore had pointed his gun at them.
When officers approached Isadore's bedroom, he shot them through the door.
Police then retreated from the home and called for backup from a Special Weapons and Tactics team (SWAT) who tried to negotiate with the suspect.
"After it was evident negotiations were unsuccessful," police said, they released gas into his room through a window.
"Shortly afterwards, a S.W.A.T. entry team, inside the residence, breached the door to the bedroom and threw a distraction device into the bedroom," the police statement reads. "Isadore then began to fire on the entry team and the entry team engaged Isadore, killing him."
As CNN notes, it's unclear what distraction device police used. Only 8 percent of the 53,000 people over 100 in the U.S. are over 104.