That is where the arming of police will help.
At the moment if a crime was happening on my front door and I called the police, if I mention there is a female with the offenders, the police will have to delay their response to wait for a female officer. If it is a group of males and the only nearby officers are female they cannot come to the scene. If I mention one of them has a weapon, be it a knife, stick or a glass bottle. Then they have to wait for a team of officers with correct protection and in cases of a gun then they would wait for armed response teams, which could take upto an hour depending on the area.
But if the police patrolling had weapons and were trained, they could respond instantly and solve the problem. Or even if they were armed then knowing that fact would more than likely deter the offenders.
The weapons in question would not even need to be lethal, maybe rubber bullets or balls loaded with tear gass similar to the ones bounty hunters use in the US.