Online, the 33-year-old wrote: "Chief Nunez, your (expletive) awesome. Thanks for the long talks over the years when I was an explorer, college student, Naval officer, and Police officer. Your are a great leader and carry your heart on your sleeve."
Unlike others Dorner named and threatened to kill because of his dismissal from the LAPD, Nunez was praised, and that was something he found disconcerting.
"You don't know what to think when someone thinks of you as a mentor and then they turn out to be cop killer," Nunez said.
While attending John F. Kennedy High School in La Palma, Dorner was part of the police department's explorer program.
"He was a hard working person and he would take on leadership responsibilities," Nunez said.
As Dorner was named as the suspect in the murders of Monica Quan and Keith Lawrence, Nunez got a call from Irvine police asking him about Dorner's past.
"My head was reeling, I had no idea it was the same person," he said.
Nunez then remembered Dorner had been by his department less than two weeks before the first murders to drop off a package and a note.
"He was telling me he was terminated and he wanted to apologize for not having time to talk to me about it, and wanted me to know he didn't do what he was accused of, at least in the administrative investigation they did on him," Nunez said.
Nunez says the package contained a CD with video from one of Dorner's LAPD interrogations, which he turned over to Irvine police.
Nunez says the death of Dorner provides some relief.
"But at the same time it's been profoundly sad because it cost another deputy their life," he said.