Federal prosecutors say their investigation into the Massachusetts State Police overtime scandal has been hindered because they have been unable to look back at traffic citation records from prior to 2015. These records, they say, may show evidence of earlier overtime fraud. The Boston Globe discovered and reported that the State Police had destroyed traffic citation records from 2014 after an internal audit was already underway. Greg Sullivan of the Pioneer Institute served as Massachusetts' inspector general for 10 years. He is raising questions about the destruction of those records. He spoke with WGBH All Things Considered anchor Barbara Howard. This transcript has been edited for clarity.

Barbara Howard: The State Police told the Globe that destroying those records was routine. Is that so?

Greg Sullivan: It's anything but routine. It would be routine for a criminal to destroy records during an investigation, but not for police officials. In order for these records to be destroyed, permission had to be given by the state record retention board. That's a system of law that's set up just for this reason.

Howard: Did that happen?

Sullivan: No. They failed to ask for it. Those time-stamped tickets represented critical evidence. That was the means by which the troopers were able to show they were working, when in fact, they weren't working. So it's really critical information that was destroyed.

Howard: Who in the State Police would have ordered the destruction of those records?

Sullivan: Well I hope that that would become the subject of a investigation by the attorney general's office. These records that we're talking about being destroyed, that happened in January of 2018.

Howard: So by that time, the people investigating knew full well not to destroy evidence, you’re saying.

Sullivan: Yes. The people who made the call to destroy these records did something, in my view, that was 10 times worse than the actual offenses themselves. That is, in the middle of an ongoing investigation, they destroyed critical evidence and did not get permission to do so as they were required by law.

Howard: You know, there's been a lot of talk about, 'At what level does this corruption stop? Is it just the low-level troopers who have pleaded guilty? And was this systemic? Was it corruption in the upper ranks of the State Police?'

Sullivan: Certainly this most recent turn of the page of the scandal shows that somebody higher up had to have approved the destruction of records. A line state trooper is not in charge of protecting public records at the State Police. That's going to be officials higher up who would have been fully cognizant of the fact that there were big time investigations going down.

Howard: Well if you were still inspector general for the state, what sort of action would you like to see taken on this at this point?

Sullivan: Well I think what should happen is there should be a full scale investigation to go and look at this as a very, very serious matter, as a potentially criminal matter. It should be conducted by the state attorney general, by the state inspector general. And I'm certain that the U.S. attorney's office will be following up on this, too.

Howard: What do you expect to be the outcome?

Sullivan: I don't know what to predict. One thing I would forecast is that the investigators who will be looking at this will be highly skeptical of a claim that this was a routine matter. They never even bothered to go to the state board as they were required by law to do. They just had the records destroyed. You know, they say that it's better to ask forgiveness than permission. But I don't know that there's going to be much forgiveness on this transaction. It doesn't look good.

Howard: That's Greg Sullivan with the Pioneer Institute. He served for 10 years as the state's inspector general. He spoke with us about the overtime abuse scandal at the Massachusetts State Police. State Police spokesman Dave Procopio provided a statement to WGBH News. He says that there was no malfeasance on the part of State Police. He says destruction of the 2014 records was part of a routine process, and that as far as the State Police knew, no criminal investigations were underway when those records were destroyed.