Story highlights Teen's brother says friend is "devastated"

Premila Lal was shot and killed by a family friend

The 18-year-old is remembered as a good student and athlete

Police call the shooting death "unintended and extremely tragic"

The combination of a gun and a surprise gone wrong left a beloved 18-year-old track star dead, authorities in Longmont, Colorado, say.

The incident happened Friday when Premila Lal and her 12-year-old cousin decided to play a joke on Nerrek Galley, a close family friend, according to Lal's father. The Lal family had recently moved, and Galley had been keeping an eye on the recently vacated home.

Lal and her cousin snuck into the house just before 8 p.m. unbeknownst to Galley, who was playing video games with Premila's 15-year-old brother, Pranil.

Galley and Pranil heard a noise and went to check it out, the brother told CNN affiliate KUSA on Sunday.

"We thought maybe there was an intruder in the house and maybe some people knew we moved, and they were coming to check if we got everything so we started clearing the house," Pranil told KUSA.

But the intruder turned out to be Premila, who jumped out of a closet as a harmless joke, according to her family.

"The door opened and she kind of, like, screamed and then Nerrek pulled the trigger," her 12-year-old cousin told KUSA.

Authorities say the family's description of what happened is consistent with their investigation.

"All the witnesses had consistent statements," Commander Jeffrey Satur of the Longmont Police Department told CNN Sunday.

A neighbor told CNN's affiliate KDVR that she saw the group rush out of the home, screaming. Lal was admitted to a hospital and was pronounced dead about an hour later.

Galley is being held on charges of reckless endangerment, child abuse and providing a gun to a juvenile because Lal's 15-year-old brother had access to the gun, police say.

So far Galley has not been charged in Lal's killing.

A court hearing was scheduled for Monday.

"We lost a daughter, so we don't want anybody else to lose their son, you know, especially when it was accident," Premila's father, Praveen Lal, told Denver TV station KCNC.

Galley's attorney was not available for comment Monday. No public statement has been made on his behalf.

Pranil told KUSA that Galley "is devastated right now."

Police said they do not suspect the involvement of alcohol or drugs.

The teen's death was "unintended and extremely tragic," police said in a statement.

Lal was honored at a weekend cross country meet at her alma mater, KDVR reported.

Her family described her as an athlete, popular girl and strong student.

Longmont is a former farming community at the foothills of the Rockies. More recently, the community of just under 90,000 has developed high-tech jobs.

The town was already stunned by a murder-suicide a day earlier. An 80-year-old man shot his 72-year-old wife before killing himself, police say.

Before last week, Satur said, he can't remember when the last shooting was. "It's been a tough weekend."