When Trump said that he meant a Faux News article about immigrants in Sweden, I went and checked some of the claims made in the article. None of them held up, most notably the notion that Sweden is some kind of rape capital of Europe due to an immigrant menace. After checking some other sources, I found that the wiki article summarized the situation pretty well, as regards how sexual assaults are reported in Sweden. I think this part was interesting....
The legal definition of rape in Sweden is described in chapter 6 in the Swedish Penal Code. Historically, rape has been defined as forced sexual intercourse initiated against a woman or man by one or several people, without her/his consent. In recent years, several revisions to the definition of rape have been made in Swedish law, to now not only include intercourse, but comparable sexual acts initiated against someone passive—incapable of giving consent—because they are in a vulnerable situation, such as a state of fear or unconsciousness.
In 2014, there were 6,700 rapes reported to the Swedish police—or 69 cases per 100,000 population—according to the Swedish National Council for Crime Prevention (BRÅ), which is an 11 percent increase from the previous year. The number of convictions has remained relatively unchanged since 2005, with approximately 190 convictions on average each year.
There have been several international comparisons made, placing Sweden at the top end of the number of reported rapes. However, police procedures and legal definitions vary widely across countries, which makes it difficult to compare rape statistics. For example, Sweden reformed its sex crime legislation and made the legal definition of rape much wider in 2005, which largely explains a significant increase in the number of reported rapes in the ten-year period of 2004-2013. The Swedish police also record each instance of sexual violence in every case separately, leading to an inflated number of cases compared to other countries. Additionally, the Swedish police have improved the handling of rape cases, in an effort to increase the number of crimes reported. Raised awareness and a shifting attitude of sexual crimes in Sweden,[note 1] which has been ranked as the number one country in gender equality, may also explain the relatively high rates of reported rape.
-- from Wikipedia, "Rape in Sweden"
When I fact-check hysterical Brown Menace sorts of articles, this is the sort of result I usually get.