Most of the focus so far in the scandal at the Registry of Motor Vehicles has been on finding out what went wrong. Now attention is starting to shift to why.

On the Codcast, Sen. Eric Lesser of Longmeadow and Paul Levy, one of the state’s most experienced managers, discussed why an agency would ignore all the warning signs and allow notices about Massachusetts driver violations in other states to pile up unattended. The situation only came to light when a Massachusetts driver who should have had his license suspended because of a drunken driving arrest in Connecticut plowed into a group of motorcyclists in New Hampshire, killing seven of them.

Lesser is vice chair of the Legislature’s Transportation Commission, which heard seven hours of testimony last week from an assortment of Registry officials who acknowledged they were aware of the backlog of out-of-state violation notices but did little or nothing to address the problem.

“What was clear from the top is that a culture had developed where this was not a priority,” he said. “There were clear warning signs along the way and there were red flags along the way and there were audits that flagged these issues. But for whatever reason, the can was kicked down the road and it wasn’t made a priority to get that backlog resolved.”