Samantha Keithley sent a series of disturbing text messages late Sunday, complaining about her husband to a longtime friend.

"Kirk has lost his mind Kristin," she wrote in one text, talking to friend Kristin Kellin. "He's literally losing it. He's been harassing me for the last 6 hours and I've asked him repeatedly to just leave me alone because I'm sick."

Keithley, 33, wrote that she had tossed her ring outside, a reference to a wedding ring.

That was 11:50 p.m. The texts were not seen for hours. Sometime near midnight, authorities say, she was shot to death by her husband, Kirk Keithley, a 39-year-old Hillsborough County sheriff's deputy, who then fatally turned the gun on himself.

"She was an amazing mother and an amazing friend and amazing wife," Kellin said in an interview with the Tampa Bay Times. "This is horrible."

Pasco County deputies were called to the home at 17364 Terrazzo Way when a 14-year-old boy ran from the house and alerted 911 after hearing an argument and a shot fired inside the home, Pasco Sheriff Chris Nocco said at an early morning news conference.

Once deputies arrived, they found the body of a woman on a couch, Nocco said. They went upstairs and found three other children safe, but the deputy dead in another room from an apparent self-inflicted gunshot wound, according to a preliminary investigation.

Nocco said Keithley did not appear to have used his service weapon in the shooting, and the Pasco Sheriff's Office had not previously been called to the home.

"Just pray for these kids," he said. "It's Monday morning, there's a lot of people waking up, getting ready to go to school, and there's four children trying to put their shattered lives together and figure out what just happened to them overnight."

The Keithleys were married about six years, Kellin said. Together, they had Alivia, 4, and Avalyn, 2. Mark, 14, was Samantha's by another father and Peyton, 7, was Kirk's by another mother, Kellin said.

Kirk Keithley "was a quiet guy, but he wasn't irrational," she said. "Everybody has problems, but not anything that would cause him to shoot her in the head. He was a very quiet person. I can't believe he did this. She doesn't deserve this."

Kellin said she had known Samantha Keithley since their early days at Bloomingdale High School. The two graduated from there in 2003. Keithley went to nursing school at Hillsborough Community College about five years ago but worked at the Seminole Hard Rock Hotel & Casino, where she had recently been promoted into a management position.

"She enjoyed life," said Kellin. "sporting events, traveling. She had her best friends, five of them, myself included. She was a very amazing person. She liked concerts."

The cream-colored, two-story home the couple shared is in the new Bexley subdivision, northeast of the intersection of the Suncoast Parkway and State Road 54. Records show the two bought it in February for $322,000.

On Monday, it was ringed in crime scene tape.

As investigators hauled paper bags of evidence from the home, passersby gawked at the activity. A man and woman crossed themselves and murmured a prayer as their dog led them away.

Clues to a family's life filled the garage: a bag of golf clubs, a red wagon, plastic bins stacked on shelves. Matching white rocking chairs sat still on porch. Beside them, a tiny purple deck chair.

A gray Honda minivan and white Mercedes sedan were parked in the driveway.

Shortly after 8 a.m., two people wheeled out a red body bag on a stretcher and loaded it into a van parked at the curb. A second, identical bag followed about 15 minutes later.

About an hour later, investigators closed the garage door and deputies rolled up the crime scene tape.

One next door neighbor declined to comment, telling a reporter she didn't know much about the family. She said few if any residents would, because everyone is so new to the neighborhood.

Joe Lupo, president of the Seminole Hard Rock Hotel & Casino Tampa, expressed grief over the death of a woman known to coworkers as Sam.

"We are deeply saddened by this tragic news," he said in a written statement. "Sam was part of our Hard Rock family for over 10 years. She was truly loved by all who knew her. Our focus now is to support each other as we mourn this devastating loss. We are broken-hearted."

Kirk Keithley's ex-wife declined to comment.

Keithley was hired by the Hillsborough County Sheriff's Office in 2009 and worked as a patrol deputy in the northeast area of the county. He had prior experience at the St. Petersburg Police Department.

In St. Petersburg, he received generally positive evaluations, his personnel file shows, although in 2008, an evaluator called his demeanor "austere" and recommended he seek out training on interpersonal skills.

A request by the Times to review his Hillsborough Sheriff's Office personnel file is still pending. The agency released a brief synopsis of his disciplinary history. It included a 2016 reprimand for "misuse of communications facilities" and a 2011 letter of counseling for an "avoidable traffic crash."

In a statement, Hillsborough Sheriff Chad Chronister said he was disheartened, adding that domestic violence "has no place in our society."

He said the agency's employee assistance program is available for struggling coworkers, and, like Nocco, he called for prayers for the Keithleys' four children.

"This is something that is impossible to comprehend for even the most seasoned person," Chronister said. "Please keep them in your hearts as we all try to make our way through this tragedy."

Pasco County Schools spokeswoman Linda Cobbe said a crisis team is on standby. The two older children attend Pine View Elementary and Sunlake High School.

Kellin, the friend, said the children are staying with family.

She called Mark, the 14-year-old, a hero. He had raced to summon help to a home where three young children were still alive.

"I know he couldn't save his mother," she said, "but he saw her lying there dead and ran to get out of the house to call 911."

A GoFundMe account has been established to benefit the children.