Why did Trump attack Jeanine Pirro over US reflecting pool ‘vandalism’?

US President Donald Trump has threatened to fire US Attorney for the District of Columbia Jeanine Pirro, after she said the government would not press ahead with criminal charges of vandalism of Washington’s Lincoln Memorial Reflecting Pool against former Olympic athlete David Hearn .

The reflecting pool project is one of several changes to the landscape of Washington, DC that Trump has pursued during his second term in office.

But following a multimillion-dollar refurbishment ahead of the 250th anniversary of US independence this year, parts of the lining of the pool were seen floating on the surface, and algae turned the water from blue to green, which Trump claimed was caused by vandalism.

Hearn, 67, was among a number of people arrested for suspected criminal damage to the “American flag blue” lining of the pool.

Pirro, however, acknowledged last week that the pool’s peeling sealant appeared to be the result of a “botched installation”, putting her at odds with the US president.

On Monday, Trump sharply criticised Pirro, who he had appointed as attorney for the District of Columbia in May last year, saying she had “choked” under pressure from a judge and “folded like an umbrella”.

Pirro met the president on Monday as he pondered firing her, but sources familiar with the matter told US broadcaster CNN late on Monday that Trump held back from firing his long-term ally.

Who is Pirro, and why has the Lincoln Memorial Reflecting Pool become a flashpoint in her relations with Trump?