TAMPA — Al Watton was a man who loved God, his country and his family. He was a Marine, a veteran of the Korean War, and a 25-year educator with Hillsborough County schools who was said to have sparked in his students a passion for learning.

In 2016, he hired a man to cut the grass in his yard. There was a disagreement about money and the man attacked the 81-year-old retiree, leaving him with fatal head injuries. Watton died in a hospital Aug. 31, 2016.

On Friday, Carlos Alberto Cordero was ordered to serve 20 years in prison for the crime, followed by 10 years probation. It was the result of a plea agreement to a reduced charge of second-degree murder.

Cordero, 50, stood at a lectern in a Tampa courtroom beside his attorney. Wearing handcuffs, he gazed downward throughout the hour-long hearing, scarcely glancing at Watton's family members as they took the witness stand.

"In short, he was a great man," said his son-in-law Jeff Sims. "And that's what makes the senselessness of this crime so hard to deal with."

The witnesses sought to memorialize for the court record the man they lost and the things he accomplished in his eight decades of life.

Alfred William Watton was born Jan. 24, 1935, to a family that grew to nine children. He was a deacon at Tampa Primitive Baptist Church. He organized a family reunion every year for more than half a century. He and his wife, Lena Ann, were married more than 50 years.

He taught a number of subjects to middle school-aged kids, including science and social studies. He retired as an occupational specialist at Woodrow Wilson Junior High School. He coached Little League and taught night school to foreign students.

"He isn't just a case number on a docket," said his daughter, Alicia Watton. "He was my dad."

He was described as quiet and humble, a man who opened his wallet when he heard that the man who would end up killing him had fallen on hard times.

"It is my prayer that I will one day forgive this man for what he did," Alicia Watton said. "I'm not there yet."

In the three years that the case was pending, Cordero unsuccessfully sought to claim his attack on the elderly man was self-defense, citing Florida's stand your ground law.

Watton had paid him $22 for yard work at his north Tampa home. Cordero argued that he was owed more. He claimed Watton pushed him and then he pushed him back. Watton fell and hit his head.

A medical examiner later determined that Watton suffered at least two severe blows, which caused his skull to fracture, and that the injuries were not the result of a fall.

After the attack, Cordero removed Watton's shorts and took his wallet, which held $120.

Lena Watton found her husband mortally injured hours later.

The self-defense claim angered Watton's family was rejected by Hillsborough Circuit Judge Laura Ward.

When Cordero had the chance to speak, he let his lawyer talk for him.

"My client has asked me to express his sorrow to the family for their loss," Assistant Public Defender Joseph Larrinaga said.

Cordero was led from the courtroom without saying a word.

Contact Dan Sullivan at dsullivan@tampabay.com. Follow @TimesDan.