Kylen Pratt, the North Philadelphia man who police say shot a man to death and set his corpse ablaze in February, did so to prevent the victim from revealing that they were involved in an intimate relationship, police said Friday.

Pratt, 20, of the 2900 block of Oxford Street, has been charged with murder and related counts in the death of Naasire Johnson, 20, who was shot in the neck and his remains set on fire.

Police found Johnson’s charred body Feb. 20 on a cobblestone trail near Brewery Hill and Kelly Drive in Fairmount Park.

Homicide Capt. Jason Smith said Friday that cell phone records were key in revealing the motive behind Johnson’s death. The evidence led to Pratt, he said, who dated women as well as men and killed Johnson to prevent him from telling anyone about their relationship.

Johnson, who was openly gay, was last seen the night of Feb. 17, said Cynthia Johnson, his grandmother, who raised him from the age of 1.

She said her grandson called an Uber and left the family’s home in West Philadelphia that evening. She did not know where he was going, but when he did not return, she reported him missing the next day. On that day, a friend of her grandson’s told her he had been in a relationship with a man called 29th Street Rich, she said. She later learned that was Pratt’s nickname, Cynthia Johnson said.

A detective, she said, told her that her grandson’s cell phone last pinged at 12:20 a.m. Feb. 18 in the 2900 block of Oxford Street, where Pratt lives.

Police believe Pratt shot Johnson at his home and moved his body to the trail in Fairmount Park and set it on fire.

“It’s a relief that they arrested someone, but at the same time I’m just so hurt,” Cynthia Johnson said. “It’s just so sad. He didn’t have to do that to him. My grandson didn’t deserve that.”

She said she believes her grandson was the victim of a hate crime, and that his killer should go to prison for life. “The way he took him out there and burned him. That’s a hate crime,” she said. “He knew what he was going to do to him.”

A 2018 graduate of the Charter High School for Architecture and Design, Johnson was working as a home health-care aide and was preparing to enroll in Community College of Philadelphia at the time of his death, his grandmother said.

“I’m in the process of trying to move because it was just him and me here, together,” she said. “Every time I wake up and see his picture and I start crying. I can’t eat, I can’t sleep. Why did he have to do that? He didn’t have to do that to him.”