In this pool photo provided by the Pierce County Sheriff's Dept., an investigator walks through the garage area, Monday, Feb. 6, 2012, in the rubble of the home in Graham, Wash., where Josh Powell and his two sons were killed Sunday in what police said appeared to be a deliberately set fire. Powell's wife Susan went mysteriously missing from their West Valley City, Utah, home in December 2009. (AP Photo/Pierce County Sheriff's Dept., Ed Troyer, Pool)
(CNN) -- A letter of reprimand was sent to the 911 operator who handled the emergency call from a social worker seeking help as Josh Powell killed his sons and himself in his Graham, Washington, home in February.
It took eight minutes for 911 communications officer David Lovrak to send a police car, and it took an additional 13 minutes for a police car to get to Powell's home, according to the letter released Thursday.
Lovrak violated several department policies and failed to recognize "many red flags" that should have led to a faster response, the reprimand said.
Powell snatched the children from a social worker delivering them for a supervised visit, locked the doors and hacked them with a hatchet before an explosion engulfed his home February 5.
The gas-fueled blast killed Powell and his sons, Charles, 7, and Braden, 5, a grisly end to a story that started with the 2009 disappearance of the boys' mother.
"You said that you have learned from this call to be more attentive to every caller and listen carefully to what they are saying and assuming nothing," wrote Diana Lock, the assistant director of the Law Enforcement Support Agency, which operates the 911 call center.
Lovrak was confused about how the social worker, who brought the two children to Powell's home for a supervised visit, "fit into the equation," the letter said.
"During the fact-finding you said that you were indeed confused and at first thought that the caller was the mother of the children," Lock wrote. "You said that you regretted sounding contentious when you said 'You can't supervise yourself.'"
The operator was also criticized for responding to the caller's question of "How long will it be" with the answer "I don't know ma'am, they have to respond to emergencies -- life threatening situations first."
His assumption that the caller was a mother involved in a custodial dispute contributed to the operator missing what "appeared to be many red flags," Lock wrote.
"When asked about this in the fact-finding you responded that custodial interference calls typically have heightened emotions and feel like emergencies to the person making the 911 call," she wrote. "You further stated that you wished you had known who Josh Powell was."
In March, investigators found Susan Powell's blood inside the family's Utah home and a handwritten will saying she feared for her life at the hands of her husband, court documents show.
The documents offered a glimpse of the evidence authorities collected that put Josh Powell at the center of the investigation into her December, 2009, disappearance.
The reprimand regarding the 911 call also listed factors that were beyond Lovrak's control.
The 911 computers have a system to quickly identify addresses known to be related to problems, but there was no "premise hazard" information for Powell's home despite his history. This "would have alerted you and the dispatcher to the need for a heightened response," the letter said.
The appropriate discipline should be corrective, not punitive, the letter concluded.
"You have undergone local and national scrutiny, have admitted your errors, and have identified the ways you will correct and improve your call handling in the future," Lock wrote.