The 4-year-old boy was punched so hard in his stomach, a prosecutor said, that the medical examiner noticed fist marks on his skin.

Assistant U.S. Attorney Cynthia Wright gave a vivid description of the bruises Kamari Zavon Taylor suffered before he died Aug. 5 at the hands of his mother’s boyfriend.

That boyfriend, Peter I. Hendy II, 33, of the District pleaded guilty Thursday to second-degree murder in D.C. Superior Court. Kamari’s mother, surrounded by about a dozen family members and friends, wept during the hearing.

Wright told Judge Ronna L. Beck that Hendy was babysitting Kamari while the boy’s mother was at work. Hendy told authorities that he became angry when Kamari disobeyed him about how far the boy could ride his scooter, court papers say.

Hendy told police that he scolded the youth after Kamari told him, “I don’t have to listen to you — you’re not my daddy,” according to court charging documents. He said he then punched the child “four to five times,” including once in the stomach.

Kamari Taylor (U.S. Attorney's Office)

Hendy then left Kamari in the apartment, in the 5600 block of Nannie Helen Buroughs Avenue NE, as he went out to sell marijuana, Wright said. An hour later, he returned to the apartment and noticed that Kamari had a “blank look” on his face and appeared “spent,” she said. Instead of calling emergency services, Hendy again went out to sell marijuana and left Kamari in bed, the prosecutor said.

When Hendy returned to the apartment for the second time, he noticed that Kamari wasn’t breathing, Wright said. He called 911 and reported that his girlfriend’s son was unconscious and wasn’t breathing.

An emergency operator instructed Hendy on how to give the child CPR. When emergency workers arrived, Kamari was taken to a nearby hospital and pronounced dead.

Wright said in court that the medical examiner’s office determined that Kamari had died of multiple injuries to his torso. His liver was lacerated in three places, and he had two broken ribs.

Hendy stood next to his attorney, Renee Raymond of the District’s Public Defender Service, who handed him a tissue to wipe his tears.

Hendy faces a maximum of 20 years in prison when he is sentenced Nov. 22.

Prosecutors said they agreed to the plea deal, and to not ask the judge for a sentence greater than 20 years, because Hendy had admitted that he beat the child and chose to plead guilty.

Outside the courtroom, dozens of Kamari’s family members circled his mother, who continued to sob.

At one point, the family began praying, with Wright in the circle.

“Lord, heal us as only you can. Strengthen us. Protect us and give this family guidance, in Jesus’s name,” one of the family members prayed before escorting Kamari’s mother from the courthouse.