- The teenager was been arrested in London and taken to Luton by police
- Three men, described by police as black and in their twenties, are believed to have forced their way into Tony Abrahams' home at about 3am on Saturday
- The victim's wife and daughter called police after finding Mr Abrahams injured
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Lee Curley took more than 120 pictures and videos of his attacks on the girl, said to be under the age of 13.
Council workers uncovered the AK-74 concealed in the undergrowth.
The thief, who used a walking stick, was helped by a man who disabled the lock before pushing the woman away.