Section 142. Powers and duties of members of police department

The members
  of the police department, other than surgeons, in criminal matters  have
  all  the  powers of police officers under the general laws of the state,
  and they shall also have the power and it shall be their duty to  arrest
  any  person  found  by them violating any of the penal ordinances of the
  city or laws of the state, and to take such  person  before  the  proper
  city  magistrate.  Such person shall be dealt with in the same manner as
  if he had been arrested upon a warrant theretofore duly issued  by  such
  magistrate. They shall report violations of law and ordinances coming to
  their  knowledge  in  any  way under regulations to be prescribed by the
  commissioner of public safety. They shall also have, in every other part
  of the state, in criminal matters all the powers of constables  and  any
  warrant  for  search or arrest issued by any magistrate of the state may
  be executed by them in any part of the  state  according  to  the  tenor
  thereof  without  indorsement.  They shall possess such other powers and
  perform such other duties as may be provided by law or ordinance of  the
  common council.