Police in major US cities are preparing for potential unrest in case ex-President Donald Trump is arrested as part of a hush-money inquiry.
Authorities in New York, Washington DC and Los Angeles are ramping up their law enforcement presence.
A Manhattan prosecutor may charge Mr Trump over claims that he paid a porn star to keep quiet about the affair they allegedly had.
It would be the first criminal case brought against a former US president.
Steel barricades were being erected on Monday outside the Manhattan Criminal Court, where Mr Trump could be charged, fingerprinted and photographed if charges are filed this week, as US media widely anticipate.
Increased police presence has also been seen outside Trump Tower in the city.
Every member of the New York Police Department (NYPD), including plainclothes detectives, had been ordered to wear their full uniform on Tuesday (21 March) and is being placed on standby to mobilize, a police source told CBS.
The NYPD and the FBI’s Joint Terrorism Task Force have been in touch with the US Secret Service, whose job it is to protect presidents and former presidents, about how a potential arrest might take place.
Capitol Police, who protect lawmakers on Capitol Hill in Washington DC, plan to issue an emergency declaration on Tuesday, a congressional source told CBS.
The order aims to increase co-ordination with other law enforcement agencies.
More civil disturbance officers will also be on standby, though the congressional source said there was no specific threat and that the order was proactive.
