Scot Peterson, the disgraced Broward County sheriff's deputy who did not confront Nikolas Cruz as he opened fire at Marjory Stoneman Douglas in February, declined on Thursday to testify before a public safety commission investigating the massacre.

Peterson, 55, would've been asked why he didn't enter the Parkland, Florida school building where 17 people were killed in one of the largest mass shootings in modern U.S. history.

SCOT PETERSON, DISGRACED PARKLAND SCHOOL COP, STARTS GETTING $8,702-A-MONTH PENSION

The school resource officer's attorney, Joseph DiRuzzo, instead appeared before the commission. He told them that earlier Thursday he filed a lawsuit to stop the 14-member panel's subpoena.

The commission, which is meeting this week to dissect the Feb. 14 shooting, criticized Peterson on Wednesday, as they believe he could've prevented at least six deaths if he entered the building immediately. Instead, Peterson took cover from Cruz's gunfire and never went inside.

"He was a cop in name only," Polk County Sheriff Grady Judd said. "If he had been a real cop, he would have run in there with that gun."

One victim's parent told DiRuzzo that Peterson "didn't do his job. My daughter should be alive."

Peterson told investigators he heard only two or three shots and didn't know whether they were coming from inside or outside the three-story freshman building. That is contradicted by radio calls in which he correctly identifies the building as the shooter's location. Bullets also came out a window almost directly above where he took cover. About 150 shots were fired.

BROWARD DEPUTY SCOT PETERSON SEEN STANDING OUTSIDE DURING FLORIDA SCHOOL SHOOTING IN NEW VIDEO

He resigned soon after the shooting instead of facing possible termination.

In the aftermath of the shooting, Peterson defended his actions, questioning how people could "keep saying I did nothing?"

In the minds of the public, Peterson said, you are either a “hero or a coward, and that’s it.

“I’ve cut that day up a thousand ways with a million different what-if scenarios, but the bottom line is I was there to protect, and I lost 17,” he added.

The Associated Press contributed to this report.