It's being described as a preliminary move.
There's no indication that charges are about to filed for the takedown or for Casebolt pulling his gun on two unarmed teens who ran up near him.
Casebolt's police union attorney said stress from handling two earlier calls that Friday caused his emotions to get the best of him.
FOX 4 wanted to know more about the psychology of stress.
FOX 4's Shaun Rabb talked to a forensic psychologist who says stress can add up to a point where the brain changes and you no longer have control over how you think, act or react to what's happening around you.
Forensic psychologist Robert Gordon agrees with Casebolt's attorney that the two calls he responded to before the pool party investigation, a suicide and attempted suicide, raised Casebolt's stress level.
"Of course they did, because stress is cumulative, so the two traumatic experiences he had earlier that evening certainly lowered his threshold or trigger for an acting out response due to stress," said Gordon.
Attorney Jane Bishkin said Casebolt didn't want to take the call at the pool party, and Dr. Gordon says he shouldn't have, answering what would have been three intense calls in about 90 minutes.
"He should have grounded himself, and it's not just the police officer; McKinney Police Department is excellent," said Gordon. "But the problem is when you have too much stress, you have to say, I'm not gonna fly that plane, I'm not gonna teach that class, I'm not gonna take that third call. You'd be a hero if you did it, but most of us can't manage the stress."
"It doesn't excuse what happened, but it helps us understand the framework of what was going on?" said Rabb.
"We cannot and must never excuse violence to young people or you know, a police officer," said Gordon. "We give him or her the right to exercise force, reasonable force in a situation, but if we don't teach them, train them, not just give them a psychological before they're hired, which we do, but we don't train them, when does that level of stress becomes so great that it masks your good judgment?"
Attorney Mills said Thursday that he has spoken with Casebolt, adding there's still a lot that needs to be explained to the public about everything that led up to the pool party incident and all of the moving parts of the pool disturbance itself.
While the administrative investigation ended with Casebolt's resignation, his leaving the department would not stop any criminal investigation that's underway, and his hiring suggests that Casebolt may be concerned that criminal charges could be coming.