“In light of the gravity of the case, we have formed an investigation task force,” the Seoul Metropolitan Police Agency said in a statement.
Opposition lawmakers visited the National Police Agency, urging the police to reinforce security near the court.
Police plan to deploy “100 per cent of available personnel” and are prepared to mobilise “all available equipment” on the day of the verdict to prevent clashes near the court, according to a police report seen by AFP on Thursday.
About 14,000 officers from 210 riot police units – more than half of the entire national riot police force – will be stationed in the capital Seoul.
“Plainclothes officers will be positioned inside the Constitutional Court, while police special forces will remain on standby in surrounding areas,” the report stated.
Police have restricted access to 22 rooftops near the court and the area has been designated a “no-fly zone” with authorities preparing “anti-drone equipment”.
The country’s acting police chief has said previously the area around the court will be designated “a protest-free zone”.
Police officers are also undergoing additional training involving the use of pepper spray and batons, with the force also considering deploying special units to “respond to bomb threats”.
In addition to the impeachment verdict, Yoon also faces a criminal trial on charges of insurrection for declaring martial law in December, making him the first sitting South Korean president to stand trial in a criminal case.
He was detained in a dawn raid in January on insurrection grounds, but was released in early March on procedural grounds.
His supporters have been out protesting every weekend, with tens of thousands taking to the streets demanding the court reinstate him, with Yoon’s release from detention appearing to invigorate his backers.
