The first youth crime commissioner has said she was "truly sorry for any offence" caused as she stood down from her role following messages she wrote on Twitter.
17-year-old Paris Brown from Sheerness, Kent, was appointed to the £15,000-a-year post only last week.
Speaking at a press conference in Maidstone, Kent, Miss Brown said she had "taken the decision to decline the offer of the position" as she felt recent media attention would affect her ability to carry out the job.
She added: "I am truly sorry for any offence I have caused."
Miss Brown said: "I have made the decision to decline the offer of the position of Kent youth police and crime commissioner.
"I have made this decision after a great deal of thought and consultation with my family.
"As I made clear over the weekend, I accept that I have made comments on social networking sites which have offended many people. I am really sorry for any offence caused.
"I strongly reiterate that I am not racist or homophobic. I have fallen into the trap of behaving with bravado on social networking sites. I hope this may stand as a learning experience for many other young people.
"I now feel that in the interests of everyone concerned, in particular the young people of Kent who I feel will benefit enormously from the role of a youth commissioner, that I should stand down as I feel that the recent media furore will continue and hamper my ability to perform the job to the level required.
"I would like to thank those people who have sent messages of support and understanding.
"I wish the commissioner, Kent Police and the person eventually appointed to this role every success.
"Finally, I ask for the time and space to recover from what has been a very difficult time and to allow me to move on."
Kent Police and Crime Commissioner Ann Barnes said: "It is a very, very sad day."
Miss Brown was "an extraordinary young person with exceptional skills and a proven track record with working with young people" who has "turned down the position of a lifetime", according to Mrs Barnes.
"I was not recruiting an angel. I was not recruiting a police officer. I was recruiting a young person, warts and all," she said.
"It is personally sad for Paris and her family. An enthusiastic young woman with exceptional skills and a proven track record in working with young people has ended up in a position where she has turned down the job of a lifetime for her.
"At this early stage in my comments, I would like to say that Paris and her family have requested to be here today. That in itself shows the degree of her moral courage in facing up to the circumstances of the last few days and is a reflection on her true character."
Kent Police is investigating the apparently violent, anti-gay and racist social media messages written by Miss Brown between the ages of 14 and 16.
The force said complaints have been made and that it was making inquiries before deciding whether any offences were committed.
Miss Brown has denied being homophobic, racist or violent, and has since deleted the tweets.
Mrs Barnes came to the teenager's defence, stressing that her recruitment to the position was not a gimmick.
Mrs Barnes, 67, who was to pay £5,000 of Miss Brown's salary from her own pay, previously said she does not condone the nature of the Twitter messages but asked for some perspective given Miss Brown's age.
The teenager was one of 164 applicants for the job, intended to provide young people's views on policing, and she was the best one and a "confident and articulate woman", she said.
The teenager's personal Twitter account was not vetted before the recruitment, Mrs Barnes admitted.
Mrs Barnes refused to step down herself, adding: "All I will say is that I am not a quitter by nature."
Explaining why she stood by Miss Brown, she added: "When I looked her in the eye and listened to my gut instinct, I believed her not to be the person reflected in what is for some people the parallel universe of social networking."
She also praised Miss Brown's "immense courage" in standing in front of the national media and apologising profusely.
"Not many people in public life would have the guts to do that," Mrs Barnes said.
"Many hide behind a press release of apology and run for cover."
She added: "There have now been complaints from a number of people to the police who believe that the tweets quotes may constitute an offence.
"This will undoubtedly lead to sustained media interest and Paris and her family have reluctantly decided to decline the offer of employment for the reasons stated in her statement."
Referring to the comments, Mrs Barnes went on: "Posting messages is part of their everyday lives and I'm sure many people today would not have the jobs they are in if their thoughts in their teenage years were scrutinised.
"It's a very sad world that Paris is now hostage to those comments she made.
"I do not condone them at all. But I do feel they should not shape her future. Everyone makes mistakes."
She added: "I totally accept that the media have every right to be inquisitive and investigative. It is their job to break stories.
"However, particularly in the shadow of Leveson, I do not believe it is their job to break people - particularly when they are as young as Paris.
"The newspaper who broke this story invited Paris for a feature interview one and a half hours long - the front page article was a result of a last minute question by the reporter which Paris answered honestly and fully explaining where possible the context. Little else was reported from the interview."
She also said she wanted the opportunity to explain why she wanted to create a youth commissioner role.