Before he was shot and killed on the University of Arizona campus last October, Dr. Thomas Meixner served as the head of the Department of Hydrology and Atmospheric Sciences.

KGUN 9s Ryan Fish sat down for an interview with the man who took over for him, Interim Department Head Chris Castro.

Just two average guys trying to run a world-class department, was how he described his time working as associate Department Head with Meixner, interacting with him nearly every day.

I miss my friend, said Castro. And I think about him every day. And I hope that in the shoes that I was forced to fill, Im doing the best I can.

Before last Octobers tragedy, Castro says, he was a victim of harassment from the alleged shooter.

Castro was not at the Harshbarger Building on the day of the shooting, but the tragedy left him devastated. He says he developed acute post-traumatic stress disorder (PTSD).

I couldnt concentrate well, he recalled. Couldnt sleep. I had survivors guilt. I was teaching a class and just to get through the semester because I couldnt get through an entire lecture, I had the students watch recorded lectures of me that I had from the pandemic.

I was really a different person.

Castro says now, a year later, there are good days and bad days. Part of his healing process is being involved with the efforts to make campus safer.

There is a greater eye now toward addressing problems in communications and threat assessment management, he said. It makes me feel hopeful.

But he also tells KGUN, there are a lot of challenges the school still needs to work through.

If independent investigations determined there were failures, then there needs to be accountabilities for failures in matters of life and death, Castro said.

When asked who should be held accountable and how, Castro responded that its up to UArizona leadership to make those calls, based on the information from the third-party investigations.

As far as his own challenges dealing with the trauma, Castro takes wisdom from Meixner.

Tom said something once: He said, Dont let perfection be the enemy of good, said Castro. And so working through a tragedy, you have everything go wrong. And nothing is perfect. And no one is going to completely like the decisions that you make. But all you can do is you just proceed with compassion, love and humility every day. And you make the decisions the best way you can.

With that in mind, Castro thanks his department, the Meixner family and the UArizona community.

[Theyve] meant my ability to keep going, he said. I have been extended love and comfort in ways that I didnt, I couldnt have ever imagined.

Were here. Were still strong. Were not defined by this tragedy. But were resilient and were moving forward.