UPPER MARLBORO, Md. (WUSA) -- We now know the identity of the 17-year-old girl shot and killed inside her Upper Marlboro home. The principal of Charles Herbert Flowers High School says she is Amber Stanley -- a senior at that High School. She was an honor student who hoped to attend Harvard University next fall. Now, her classmates say they just can't believe the girl with the big smile is gone.

Early Thursday evening, a couple of dozen detectives were back out canvasing the neighborhood and passing out posters offering an up to $25,000 reward. Investigators admit that right now, the murder is a real mystery. They have no suspect, no motive, and no explanation.

News spread fast at Charles Herbert Flowers High School about Stanley's death. The principal made the official announcement at the start of the school day.

"Students came up and told stories of Amber and how she was an affable child with an infectious smile. And she will be missed by all a great deal," said principal Gorman Brown.

Prince George's County School Superintendent Dr. William R. Hite Jr. issued a statement after Amber Stanley's death:

The Prince George's County Public Schools (PGCPS) community is tremendously saddened by the death of Charles Herbert Flowers High School honors student Amber Stanley. This young girl had a bright future ahead of her with dreams to pursue and goals to reach. We condemn the senseless act of violence that took her life and hope that law enforcement officials will quickly bring those responsible to justice. On behalf of our school system family, we extend our deepest sympathies to all who loved Amber and pray that your memories bring you comfort in this time of grief.

Neighbors told 9NEWS NOW they heard loud banging on the family'sdoor on Chartsey Street around 10Wednesday night. The 17- year-old victim was at the home with her sister, her sister's son and a foster child. Neighbors sayeveryone but the teen victim escaped through a window.Police say someone went to her bedroom and then shot Amber Stanley multiple times.

"We were told that somebody entered the home. We don't know, I don't want to say one person, I don't want to say more than one. We know it was at least one person that entered the home," said a police spokesperson.

A few hours later, Amber's mother, who was not home at the time of the shooting, watched as her daugher's body was taken from the home she grew up in.The family has lived in the home on Chartsey Street for at least 20 years.

"The investigation is ongoing," said Cpl. Larry Johnson with the Prince George's County Police Department. "Still looking for a suspect, still looking for a motive. If anyone has information, seen anything suspicious in the neighborhood, please provide that information to the police department."

Cpl. Johnson said you can call the department or call Crime Solvers at 866-411-TIPS with any information.

Several neighbors told WUSA that earlier this week police were called to the home regarding a complaint from the foster child. They say there had been friction building for months between that foster child and Amber's mother, but homicide detectives wouldn't talk about it, except to say that they are investigating every possible angle.

Stay with WUSA9.com and 9NEWS NOW for updates.

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