Eddie Leonard Sr. remembered changing his baby cousin’s diapers 30 years ago and, later, watching his cousin and son play together as they grew.

On Friday, Leonard and his family watched as that same cousin, Charles Coates, was sentenced to prison for his son’s murder. D.C. Superior Court Judge William M. Jackson sentenced Coates to 33 years behind bars after a jury in September found him guilty of murder in the Feb. 20, 2011, shooting of Eddie Leonard Jr.

Leonard, 32, was killed in an alley, authorities said, after Coates lured him there after a dispute. The killing, Eddie Leonard Sr. said, has divided a once-close family. “This hurts so much,” he said during Coates’s hearing. “I put Pampers on you. I protected you. Eddie looked up to you. We were a family. How could you do this?”

Coates, 43, smiled and shook his head.

He had initially told police that another person shot Leonard in the head with a .380-caliber handgun. Authorities said he even had his mother, the elder Leonard’s first cousin, call Crime Stoppers with the tip. After his arrest, Coates told the jury that he was holding the gun that killed Leonard but that it discharged accidentally.

On Friday, Coates turned to face several rows of family members sitting in the courtroom and said he did not kill his cousin, a father of five. who was known as “Little Ed.”

“You turned an accident into a crime,” he said. “But I understand your position, and I don’t begrudge you.”

Leonard said that even with the verdict and sentence, Coates’s continually changing accounts have left his relatives feeling as though they may never know exactly what happened in the alley behind the 400 block of 24th Street NE.

“This might have been easier if a stranger had killed my son,” he said later. “But this was family. Family doesn’t kill family.”