>
>He claims that one reason FOR this phenomenon could be changes in
>demography. The number oF young people, who are the group that commits
>crimeS most often, is DECREASING.
>
>He claims that most crimes are the result of unemployment. IF unemployment rates were low, XXX crime rates would
also DECREASE.
>
>He claims that (usage of) new technology helps much to reduce crime.
>
>He claims that the police's attitude to their work has changed since
>the Eighties. They HAVE improved their methods and are more succesSful in
>what they are doing/ in chasing offenders.
>
>The attitude of ORDINARY CITIZENS to crime and offenders has changed.
>People have become more willing to BECOME INVOLVED in some actions
>that should help to reduce crime.
Można by jeszcze wprowadzić kilka poprawek stylistycznych, ale one nie są bezwzględnie konieczne.