uwantme2killhim? (2013) on Netflix

Plot summary

Detective Inspector Sarah Clayton tries to establish why a British schoolboy, Mark, would want to stab John, though the two are said to be friends. As she looks into the pair, she finds that Mark spends his time in online chatrooms, where he becomes fascinated with Rachel, a woman he meets in one of them. At Rachel's prompting he makes friends with her brother John. Mark falls for her, sympathizes with her accounts of abuse at the hands of her boyfriend Kevin, and accepts that the two of them cannot meet, since she says she is in a witness protection program.