(CNN) - A mass shooting with 12 people dead is probably the last way that Geoff Dean wanted to end his 40 years with the Ventura County Sheriff's Office.
Dean is stepping down after seven years as sheriff just as a gunman went on a rampage Wednesday night at the Borderline Bar & Grill in Thousand Oaks, California.
"It can't be any worse," Dean said of his final hours on the job.
Near the end of a news conference later Thursday, Dean casually told reporters he was retiring at midnight Friday.
"But I will certainly be a part of the family."
That family included Ventura County sheriff's Sgt. Ron Helus, who was among those killed at the bar late Wednesday.
Helus, 54, had been with the department for nearly three decades and was nearing his retirement, Dean said.
"They're mourning," he said of the sheriff's office, which has about 700 officers. "They're sad. It's awful. Ron was a great guy. He was close to everybody. He was a hard worker, and our hearts are broken all over."
The deputy was married and had a son.
"He went in there to save people and made the ultimate sacrifice," Dean said of Helus.
Helus usually spoke with his wife on the phone several times during his shifts, Dean said. The deputy was on the phone with her shortly before entering the bar.
"Hey, I have to go handle a call," Dean said Helus told his wife. "I love you. I'll talk to you later."
Dean believes Helus and other officers saved lives by going into the packed bar.
"It could have been much, much worse," the sheriff said.
A lifelong Californian, Dean was born in Los Angeles and raised in Simi Valley, according to the sheriff's office website.
He and his wife of 31 years, Marlene, have two children: Lindsey, 29, an attorney; and Andy 26, who's in marketing and sales.
"We've got to do something about the hate," Dean recalled telling members of a local synagogue after the mass shooting at Tree of Life synagogue in Pittsburgh.
"And we've got to do something to just spread the love and reach out and help people and be patient with them and understand them because this will touch so many lives around our community."