Video report by ITV News Correspondent Angus Walker
The prime minister said tackling knife crime was among his priorities and promised tougher sentences for violent criminals.
Since taking over at Number 10, Mr Johnson has said he would invest £2.5billion in creating 10,000 new prison places to ensure prisoners get the sentences they deserve.
ITV News Correspondent Angus Walker explains why Boris Johnson's pledges could be a sign of an upcoming general election
It is part of the prime minister's initiative to bolster law and order in the country, as he was already pledged to recruit another 20,000 police officers over the next three years.
The unveiling of another major domestic policy will only fuel rumours of an upcoming snap general election.
Mr Johnson's new policy announcement comes just days after a police officer was stabbed with a machete in east London.
On Saturday, a West Midlands police officer was run over in Birmingham and is now in a serious condition.
Writing in the Mail on Sunday, Mr Johnson said it was the "first duty" of the government to protect the public.
He said: "We need to come down hard on crime. That means coming down hard on criminals. We need to reverse the balance of fear. I want the criminals to be afraid - not the public."
Under the new plans, it will allow police to use stop-and-search powers in an area without the authorisation of a senior officer.
He acknowledged the move would be controversial but said it would have the support of parents of children at risk of being involved in knife crime.
Mr Johnson also said investment in the prison system - which has been backed by Chancellor Sajid Javid - was "long overdue".
He wrote: "In the past five years, we have seen literally hundreds of convicted rapists who have come out of prison commit another sexual offence.
"This cannot go on. I am afraid that as a society we have no choice but to insist on tougher sentencing laws for serious sexual and violent offenders, and for those who carry knives.
"Our first duty is to protect the public in the most basic way - and that means taking such people off the streets."