Murder rates soar in major United States' cities ... but no one knows why

New numbers show that murder rates are rising sharply across the U.S. — but no one can seem to explain why.

According to a recent New York Times report, at least 35 major cities have reported a spike in murders, violent crimes or both.

In St. Louis murders have risen by 60% and Baltimore by 56% since the same date in 2014.

Last month in New Orleans, 120 people were killed by late August -- that's compared to 98 during the same time last year.

Milwaukee, Wisconsin saw the biggest increase at 76%. The city has already reported 104 murders, compared to 59 in all of 2014.

See photos of cities where murders have spiked:

Homicides in cities like Los Angeles and Newark have remained relatively steady and urban bloodshed, as the Times calls it, remains far below the peaks of the late 80s and early 90s.

As for a reason for the increase, some theories include an increase in gun ownership, less aggressive policing, young people settling disputes with violence, gang-related killings as well as an increase in killings being carried out insides homes — which are "difficult crimes to predict or prevent."

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