Many people have been trying to understand what the local, state, and federal police did after they arrived at the Robb Elementary School while an active shooter was killing children and teachers. And they wonder about conflicting accounts from officials.

The editorial board of the Washington Post says that Governor Abbott of Texas must create an independent commission. Frankly, Governor Abbott is so pro-gun that it’s hard to imagine that any commission appointed by him would produce anything but a whitewash of his vicious policies, which made it legal for an 18-year-old to buy military assault weapons and to carry them openly. His actions and policies should be part of an independent investigation, and that is not likely to happen if he chooses the commission members.

What’s needed in Uvalde, Texas, is a credible investigation by the U.S. Department of Justice and the FBI.

The editorial board writes:

When police in Littleton, Colo., responded to reports of gunfire at Columbine High School in 1999, they did what they had been trained to do: set up a perimeter, summon specially trained SWAT and hostage teams, wait for demands and allow no one, including first responders, into the building. Hours passed before the building was secured, authorities realized the shooters had killed themselves, and the wounded received medical attention. Thirteen people — 12 students and a teacher — had been slaughtered.

Columbine resulted in fundamental changes in how law enforcement responds to mass shootings. The Columbine Review Commission formed by then-Gov. Bill Owens recommended in 2001 that “law enforcement policy and training should emphasize that the highest priority of law enforcement officers, after arriving at the scene of a crisis, is to stop any ongoing assault.” Active-shooter programs in which officers were trained to immediately target the gunman or gunmen became standard police protocol.

So why did it take 40 minutes to an hour before law enforcement authorities in Uvalde, Tex., stormed an elementary school classroom to stop a gunman who had gone on a shooting rampage? It is just one of the questions that parents whose children were killed, wounded or traumatized are asking — and it is one that authorities would do well to answer with clarity and urgency.

Since Tuesday’s mass shooting at Robb Elementary School, in which 19 children and two teachers were murdered, conflicting and confusing narratives have emerged. After initial accounts that the gunman had been confronted by a school resource officer and suggestions that there was an exchange of gunfire, a Texas law enforcement officer said on Thursday that the gunman entered the school “unobstructed” through a door that was apparently unlocked. Victor Escalon, a regional director at the Texas Department of Public Safety, said that Salvador Rolando Ramos, the alleged gunman who was killed when a Border Patrol tactical team burst into the room where he had been barricaded, did not initially encounter any law enforcement officers. Why the discrepancy?

Equally troubling is a harrowing video posted to a parent’s Facebook account that shows frantic family members on Tuesday begging police to take action. “Why let the children die? There’s shooting in there,” one woman pleaded. “They’re little kids, they don’t know how to defend themselves. … Six-year-old kids in there, they don’t know how to defend themselves from a shooter!” a man cried. Parents talked about rushing the building themselves, as they said police were just standing around. One parent was tackled to the ground. A national school safety expert told Post reporters that any delay in going inside will be hard to explain.

Make no mistake: The person responsible for the murder of these little children and brave teachers is the deranged 18-year-old who fired an AR-style rifle. But it is important to know whether errors were made that might have cost some lives. What lessons can be learned that might save lives in the future if — as sadly seems inevitable — there are more mass shootings? There needs to be a full public accounting. Just as the governor in Colorado once ordered a rigorous review of the events surrounding Columbine, so should Texas Gov. Greg Abbott.