WASHINGTON — At a ceremony on Friday honoring police officers and sheriffs, President Trump praised the courage and devotion of law enforcement — and presented a not entirely accurate picture of the difficult conditions they face.

In the morning, before speaking at the F.B.I. Academy in Quantico, Va., Mr. Trump lamented the reputation of the bureau. Then, as he addressed police officers who graduated from the academy’s training program, he claimed that they and the bureau’s agents were “great people” and “heroes for all of us.”

The about-face kicked off a series of misleading statements Mr. Trump made about crime, his predecessor and immigration. Here’s an assessment.

He asked “what the hell is going on in Chicago,” where most types of violent crime have declined since last year.

Mr. Trump spoke of “the steepest two-year consecutive increase in murders in nearly half a century” in 2015 and 2016, and focused on Chicago.