Terry Strawn then killed himself near Plant City High School, just down the street from where he’d killed his daughter, the sheriff said.
Chronister reiterated details he gave during a Wednesday morning media briefing, during which he said Strawn, who was initially hired as a deputy in 1991, had no indications of behavior issues during his career, which ended last year.
Strawn was rehired this past summer as a school resource officer at Valrico Elementary School, where Londyn Strawn was a student.
“He was an exemplary employee,” Chronister said. “Again, he had just learned that we were going to keep him and retain his employment in a permanent status. He was extremely grateful (and) indicated that ‘Christmas came early.’
“During his radio transmission, (he) wanted to make sure that we all took care of each other, that we knew that depression was real. (He) alluded to the fact that he was struggling with some health and financial issues.
“He indicated that he was losing everything and at one point said that he had to go. He appreciated all the help, but he had to go. He wanted to go be with his family,” Chronister said.
Watch Chronister’s afternoon news conference below, courtesy of WFTS in Tampa.
The sheriff, who at several moments paused with emotion, urged those watching and listening to the news conference to get help if they need it.
“We all struggle,” Chronister said. “We all struggle at one point or another in our lives. But there is help. Help is available.”
Chronister begged viewers and listeners in his jurisdiction to call the Crisis Center of Tampa Bay at 211. It is free and anonymous to callers, he said.
“Just when you believe that there is no help, yes someone does care and yes there is help,” he said emphatically. “I would encourage everyone, again -- don’t do something so permanent for a temporary problem that you may be facing.”
Chronister said the radio call from Strawn came over the Sheriff's Office's main channel at 6:42 a.m. In his transmission, the deputy told dispatchers he'd killed his wife and granddaughter, and told them the location of that crime scene, Chronister said. Once Sheriff's Office investigators obtained search warrants, they went in and found Theresa and Londyn Strawn dead.
Terry Strawn said he also killed his daughter at her home, to which he gave directions. Courtney Strawn was found dead there, the sheriff said.
Watch Chronister’s morning news conference below, again courtesy of WFTS.
After reporting the homicides, Strawn told dispatchers he was going to kill himself at Plant City High School.
"A supervisor immediately got on air and did everything that they could to try to talk him down, calm him down, bring some calm to the situation," Chronister said Wednesday morning.
Around that same time, three Hillsborough County deputies located their colleague on the east side of the school, off school property.
"(They) made every attempt possible to try to convince this deputy sheriff that there was a different way, there was a different solution, not to commit suicide," Chronister said. "Unfortunately, the deputy took his life on scene in front of the three deputies."
Chronister told reporters that there had been no history of erratic behavior or behavioral problems in Strawn's past with the department. He had "glowing recommendations" and positive reviews throughout his career.
“Again, no indication whatsoever that would lead us to believe, that would lead a prudent and reasonable person to believe that this deputy would ever conduct himself in the manner that he did,” Chronister said.
The sheriff said Strawn was rehired along with several other retired deputies to work as SROs in the schools. The hirings were in response to a new Florida law passed in the wake of the Feb. 14 massacre at Marjory Stoneman Douglas High School in Parkland that requires armed security or sheriff’s deputies in all schools.
WFTS reported that no students were on the Plant City High School campus at the time of the deputy's suicide nearby. The campus was immediately put on lockdown, but it was soon lifted.
Students were kept on the east side of the campus as the crime scene was being investigated. The news station reported that a robocall went out to parents Wednesday morning informing them of the situation and reassuring them that there was no threat to students.
Chronister said Strawn's suicide was the third that his investigators had responded to Wednesday morning. It was also the second time in the past three months that a Hillsborough County deputy killed himself after killing at least one family member.
Deputy Kirk Keithley, 39, shot and killed his wife, Samantha Keithley, on Sept. 24, according to the Sheriff's Office.
WFTS reported that Samantha Keithley sent text messages to a friend just hours before her death, detailing her husband's troubling behavior.
“Kirk has lost his mind, Kristen,” a text sent at 11:50 p.m. the night before the murder-suicide read. “He’s literally losing it. He’s been harassing me for the last six hours and I’ve asked him repeatedly to leave me alone because I’m sick.
"I just chucked my ring outside," Samantha Keithley wrote.
Her friend, Kristen Kellin, did not see the message in time to help her friend.
"I didn't open it until around 2 a.m. Then I texted her back this morning around 7. It was too late," Kellin told WFTS.
The couple’s four children were in the home when their parents died, the news station said. When the shooting took place, their son crawled under the garage door to get help, Kellin said.
A GoFundMe page set up to help the Keithley children has raised nearly $80,000.
Kirk Keithley had been with the Sheriff's Office for nine years, according to a news release. Prior to that, he spent six years as an officer with the St. Petersburg Police Department.
Chronister said Wednesday that his agency has been proactive since the Keithley murder-suicide by developing a suicide awareness and prevention program. The new program starts Jan. 1.
"I truly believe law enforcement's no different than modern-day society," Chronister said. "We have to change the culture. We have to make sure that everyone knows that it's OK to ask for help.
“It’s not a sign of weakness to say, ‘Hey, I’m having a difficult time. I’m having a hard time. I need some help.’”
If you or someone you love is struggling with suicide or suicidal thoughts, you can call the National Suicide Prevention Lifeline 24 hours a day at 800-273-8255, or get more information at SuicidePreventionLifeline.org.