Jessica Nguyen, a 12-year-old honor student at Gaithersburg Middle School, was home by 3 p.m. Tuesday. Five hours later, she was dead, slain in a townhouse she shared with at least five members of her extended family.

That rough timeline, police officials said Wednesday, is what detectives are working with as they search for her killer.

The child suffered trauma to her upper body, according to police. But detectives released few details about how she was killed or how her body was found, saying they did not want to tip off possible suspects about what the authorities knew.

Police said their investigation remains broad and methodical.

“Our scope will involve any person or any situation that Jessica may have come in contact with, or found herself in,” said Capt. Paul Starks, a Montgomery County police spokesman.

The investigation began shortly after 7:30 p.m. Tuesday, when Montgomery and Gaithersburg officers responded to a call for an injury to a child in the 700 block of Raven Avenue, police said. Jessica was found dead on the floor.

The townhouse sits in a large, new development off Girard Street, about a mile north of Gaithersburg City Hall.

Detectives returned to the house Wednesday to reinspect the crime scene. They also are trying to speak with those who knew her best.

“The family is grieving, and we’re sensitive to them,” Starks said. “However, they are the source of what could be pivotal information.”

Police declined to say whether they were leaning toward a person who knew Jessica as a suspect in the killing or whether a stranger may have come into contact with her.

“We don’t want to narrow our scope right now. We don’t want to miss something,” Starks said.

Jessica was remembered warmly at her school on Wednesday. Gaithersburg Middle School PTA President Terrianne Small called Jessica “a very bright girl” who had “a bright future ahead of her.”

“She was a great kid, hard-working, always had a smile on her face,” Small said.

Neighbors described her family as friendly and quiet, always waving when people passed by their front yard.

Lynn Rundhaugen recalled trying to chop winter ice with a plastic snow shovel. A man who lived in the townhouse appeared with a metal shovel. “This will work better,” he said.

Staff researcher Jennifer Jenkins contributed to this report.