Street violence can be seen as a current legal issue because it is an issue that the legal system must deal with. The legal system must try to find ways to reduce street violence that are beneficial to the society as a whole.
It can be very difficult to prevent street violence and to do so in ways that are beneficial to society. The legal system (including the police) must try to devise strategies that can prevent street violence. This can be difficult, particularly since there is not enough money in government budgets to put overwhelming police force out on the streets at all times. Even if such strategies could be devised, they would not necessarily be good for society because the legal system is set up to catch wrongdoers and to punish them. However, this is not necessarily the most just way to deal with this issue. Street violence typically has its roots in social problems that can actually be exacerbated if the legal system simply arrests and incarcerates.
For these reasons, street violence is a legal problem. It is a problem that is difficult for the legal system to deal with.