Cleveland: Republicans meeting this week to anoint Donald Trump as their presidential candidate will try to sell the combative businessman to voters as a strong leader who can shield America from the threats of violent crime and militants.
The weekend killing of three policemen in Baton Rouge overshadowed the first day of the Republican convention in Cleveland on Monday, when party officials and Trump allies will make televised speeches to promote what he bills as a tough line on law and order and national security.
Before those deaths, an apparently targeted attack by a gunman who may have intended retaliation for police killings of black people, the theme at the convention for Monday was already set as "Make America Safe Again." Events were to include speakers discussing the 2012 attack in Benghazi, Libya, that killed four Americans, including US Ambassador Chris Stevens.
Republicans have long criticised Hillary Clinton, who was secretary of state at the time and is now Trump's Democratic rival for the White House, over her response to the attack.
Trump's wife, Melania, joined by her husband on stage, as were foreign policy hawk Senator Tom Cotton and retired Lieutenant General Michael Flynn, a national security adviser.
They were likely to promise that Trump will crack down on IS abroad and toughen up on crime at home if he wins the November 8 election.
"The theme tonight is Make America Safe Again... our goal all week is to present a picture of Donald Trump that is broader than just a campaign image," Paul Manafort, a senior aide to Trump, told reporters.
Trump lashed out after the killing on Sunday of the police officers in Baton Rouge, nearly two weeks after the fatal police shooting of a black man there and another such death near St. Paul, Minnesota sparked nationwide protests. The Baton Rouge police deaths occurred just days after five policemen were killed in an ambush in Dallas.
"Our country is totally divided and our enemies are watching. We are not looking good, we are not looking smart, we are not looking tough!" Trump wrote on Twitter.
Security was extraordinarily tight in Cleveland, with downtown streets lined by concrete traffic dividers and tall metal fences, measures given a new urgency after an attacker drove a truck through a holiday crowd in Nice, France, last week, killing 84 people.
The Cleveland police union called for the suspension during the convention of a state law allowing people to carry firearms openly. But Ohio Governor John Kasich, a one-time rival to Trump, said he was powerless to act despite the heightened security concerns.
Even gun rights advocates are questioning whether people should be allowed to carry rifles and handguns during expected protests at the convention. Trump backers as well as opponents have expressed concerns about the prospect of weapons being carried in open sight around the convention site.
Ohio is among the many states that allow licensed gun owners to carry their weapons in public, and gun rights activists, particularly in Texas, have taken to expressing that right often in large-scale events.
Trump has caused controversy and upset US allies with his plans for a temporary ban on Muslims entering the United States and a wall on the US-Mexican border. But at the convention, the party will portray the New York magnate as a breath of fresh air and a strong leader.
Republicans will also accuse Clinton of being responsible for weakening the United States in a dangerous world during her four years as President Barack Obama's secretary of state from 2009-2013.
"In a year of change, Donald Trump clearly represents the change candidate... all the problems she's campaigning against are things that came on her watch," aide Manafort said.
Trump, 70, who has never held elective office, is expected to accept the nomination on Thursday night after being formally chosen on Tuesday. His vice presidential running mate, Indiana Governor Mike Pence, 57, will speak on Wednesday.
Senior Trump aides are confident they have thwarted a rebellion aimed at denying him the nomination.
For the past week, Trump's team has worked to beat back opposition from some establishment Republicans who are alarmed by his provocative comments on immigrants and Muslims and his break with party orthodoxy on issues such as trade.
Trump supporters gave conservatives control of the party's policy platform, helping end efforts to change the rules that govern how delegates vote. A majority of delegates are pledged to Trump through his victories over 16 Republican rivals in the party's presidential nominating contests.