Detectives are questioning four teenagers over the murder of an A-level student who was stabbed to death outside a house party advertised on Facebook.
Jay Whiston, 17, was knifed on Saturday night at the gathering that was attended by about 100 teenagers in an affluent area of Colchester, Essex. It is believed details of the event were circulated on the social networking site, but that a number of uninvited guests turned up.
Jay, of Clacton, Essex, was taken to Colchester General Hospital with abdominal injuries but died shortly after his arrival, having been stabbed at around 10pm. A provisional post-mortem examination showed he died from a stab wound.
A 17-year-old boy and two 18-year-old men, all from Colchester, are being questioned at separate police stations in north Essex on suspicion of murder after being arrested a short time after the stabbing was reported. Another 17-year-old boy, also from Colchester, was arrested on suspicion of murder on Sunday night.
The victim's mother Caroline Shearer, 46, said her son was trying to protect a friend when he was attacked.
"It's every mother's worst nightmare. He was loved by everyone and so caring," she added.
"My son had never been in trouble with the police before. He hated bullies and hated people being unfair. I still feel numb but I'm starting to feel angry now. How can thugs ruin innocent lives at their will? There's no rhyme or reason to it."
Detectives from Essex Police said every teenager at the party in Marlowe Way was a potential key witness.
Senior investigating officer DCI Simon Parkes said: "Although we don't yet know the details of what went on, we're slowly piecing together the sequence of events that led to this boy's death.
"We're speaking to those who were at the party, but we're mindful that there may have been others who left either before the stabbing or in the immediate aftermath before we arrived. Everyone at this party is a key witness whether they saw anything or not and we would urge them to contact us."