A youth basketball player in Garden Grove, California, was left with a concussion after an opponent sucker-punched her and the injured girls mom claimed the attackers mother encouraged it.

I want the daughter and the mom held accountable, Alice Ham told ABCs Eyewitness News . Because this type of behavior is reprehensible and cannot happen in youth sports.

Video of the weekend club game shows Lauryn Ham, 15, and the opposing player, whose father reportedly played in the NBA, briefly getting tangled after the unidentified player attempts a 3-point shot. Both trip to the floor.

Seconds later, the two are seen walking up the court side by side and the player unloads a roundhouse punch that knocks down Ham.

Alice Ham filed a police report after the incident, which has received widespread attention .

Lt. Mario Martinez of the Garden Grove Police Department told HuffPost on Thursday that detectives have begun investigating.

The video is disturbing to watch obviously, Martinez said. He said investigators would be sharing little information about the probe because the two players are juveniles.

In the news clip above, Ham told NBC she saw a normal basketball play basically turn into a nightmare.

Ham posted footage on Instagram in which an unseen woman can be heard yelling what sounds like: You gotta hit her for that. Ham, who was not in the gym at the time, said she learned from witnesses that the person who issued the command was the girls mother.

Its pretty clear that she tells her daughter you have to hit her for that, Ham said. What that is, I dont know. I dont know what the mom thinks she saw.

Ham told CBS she is praying that Lauryn will get back on the court and do what she loves.

Lawyer Brett Greenfield, who represents the family of the girl Ham identified as the assailant, said in a statement to NBC: We are in no way trying to downplay and/or disrespect the seriousness of this situation. What is vital to remember is that these are two very young minors involved. The family recognizes the seriousness of this incident and will continue to take every necessary step to manage this in a positive way.