Investigations are ongoing following the assassination attempt on Donald Trump during a rally in Pennsylvania on Saturday.
A spectator was killed and two others were critically injured.
US President Joe Biden has made an address to the nation calling for an end to violence.
The shots that rang out on Saturday have shifted the tone in the US presidential election.
Law enforcement is on high alert on the first day of the Republican National Convention in Milwaukee.
The city has been divided into separate access perimeters for the four day event. Michelle lives in Milwaukee and says the atmosphere is quite tense.
Thousands of police officers from across the country have been drafted in to monitor the events, while President Joe Biden has called for calm in an address to the nation.
“We can’t allow this violence to be normalized. You know, the political record in this country has gotten very heated. It’s time to cool it down.
We all have a responsibility to do that”, he stated.
Former President Donald Trump has arrived in the city and is set to address the crowds on Thursday.
However, there is now speculation he might make his first public appearance since the shooting as early as today.