The Facts

• After the failed assassination attempt on former Pres. Donald Trump at a campaign event on Saturday, the Secret Service and other law enforcement agencies are facing questions about how a shooter armed with an AR-style rifle was able to get to a rooftop so close to where the presumptive Republican nominee for president was speaking.Biden also said he has the Secret Service to review all security measures ahead of the Republican National Convention, which begins in Milwaukee on Monday, adding that the investigation is underway to find a motive for the assassination attempt.