Ashley Oglesby was a good student with big dreams of one day becoming a pediatrician.

On Thursday morning, those dreams came to a brutal end when Atlanta police said Ashley’s brother, who family members said “cherished” her, stood over the 16-year-old while she slept in an East Lake duplex and shot her multiple times, killing his sister.

Marquaris Jamal Oglesby, 27, was booked into the DeKalb County jail on murder charges. As of late afternoon Thursday, detectives still had not announced a clear motive. The shooting occurred in a portion of Atlanta that is in DeKalb.

“Right now we’re not sure what led up to the homicide,” Atlanta Lt. Charles Hampton said. “It’s a very tragic scene.”

As grieving family members gathered at The Villages of East Lake, aunt Sherry Morton said her nephew “had some psychiatric problems.”

The aunt said she urged Marquaris Oglesby to seek medical treatment this week because he had been talking irrationally.

“He was talking out of his head,” Morton recalled. “When he comes to his senses he is going to be distraught because he cherished the ground she walked on.”

Police said the shooting on Greenhaven Drive occurred around 7 a.m. Thursday.

The aunt told Channel 2 Action News that when the mother woke up, her son was in the bedroom and was saying that “somebody was chasing him and the guy was shooting him and he shot back.”

Marquaris Oglesby was still at the scene when police arrived at the gated complex just west of the East Lake Golf Club. The suspect surrendered peacefully and after being interviewed by police, he was taken into custody.

Ashley was taken to Grady Memorial Hospital, where she died, police said.

Family members said Ashley attended Maynard H. Jackson High School.

“It is always the good ones,” Morton said. “She wanted to be a pediatrician. That was all she ever talked about.”

— Staff photographer John Spink contributed to this article.