About 50 relatives and friends came to the hospital emergency room to wait. Scott thought of taking photos to show BJ how many people had come to rally behind him. Doctors rushed him into surgery. About two hours later, they came out, despondent.
They told her they tried everything, but couldn't save him. "They wouldn't let me see him," she said.
BJ was innocent, police say. He happened to be in a crowd about 3:45 p.m. watching kids playing baseball when a fistfight broke out. But three teens suddenly pulled out handguns and two started to fire, said Lt. John Walker, of Southwest Detectives. Dozens of kids ran.
Another 17-year-old boy, not a student in the Philadelphia public schools, was shot in the buttocks and is recovering. Both suspected shooters, a 19-year-old and 20-year-old, are in custody, but as of Friday night had not been charged. The 19-year-old, found not far from the scene, had a graze wound to his back.
Scott, with sad, tired eyes, sat in her home, a half-mile from where her son had been shot, with her two other sons, Keith, 22, and Tyler, 14, and about 20 close relatives.
"Honestly, I'm still very numb. I'm in denial," said Scott, who works with juvenile delinquents as a teaching assistant.
"It's not real," she said. "I still expect him to come through that door and ask for something to eat. Maybe it's because I haven't seen him yet."
BJ was a homebody who loved playing basketball, football and Mortal Kombat on his Xbox.
As a kindergartner, he jumped on stage during a performance to help a shy girl read a poem when she started to cry. As a teen, he dreamed of designing video games when he grew up.
"He was a big kid at heart. He had this really loud laugh and he told corny jokes that no one got but him," his mom said as her eyes gazed off.
He sang karaoke with his mom and brothers and especially liked "Take On Me," by A-ha, "Makes Me Wonder," by Maroon 5 and Michael Jackson's "Experience."
A number of additional police officers were stationed at Overbook High on Friday. Counselors and psychologists were on hand to help students, said school district spokesman Fernando Gallard.
"They are grieving, huddled together, trying to deal with this tragedy," he said.
Under a misty rain Friday afternoon, students emerged from Overbrook, appearing pained. They described BJ as a funny, popular kid who danced and sang in the hallway to see people smile.
"He was cool. He never liked to get into no trouble," said Jamie Benton, 15.
Jamie had just left Overbrook on Thursday when the shots rang out. "Everyone was scattering everywhere, over the bridge, everywhere," she said.
Jamie ran to BJ's side.
"I saw him on the ground. But I couldn't pick him up. I was in shock I think," she said.
His friends stopped by the Scott home all day to console his family.
"I miss everything about him," his brother Tyler said with tears in his eyes. "His laugh, his smile, his friendship. He was a good brother."
The family huddled in the dining room near a sole plaque on the wall that read:
"Life is not measured by the number of breaths we take, but by the moments that take our breath away."
Darshell Scott looked at it for a moment, masking her pain with a faint smile.
She said she's too dazed, too frozen for anger.
"I just want the kid who did this to know they robbed a family and a group of friends of a very special person. A rare person."
On Twitter: @barbaralaker