Depopulation in California jails and gang members moving to the Las Vegas Valley might be contributing to the rise in violent crime, according to Metro Police Sheriff Joseph Lombardo.

There’s a “plethora” of reasons why the valley might be experiencing a hike, Lombardo said during an editorial meeting with the Las Vegas Sun, but Metro has had an increase of interactions with California gang members during arrests and investigations.

“That influx is directly related to, I believe, the depopulation of the prison system in California,” he said.

This can be traced back to Proposition 47, a California ballot initiative turned into law November 2014, Lombardo said.

In Southern Nevada, violent crime in Metro Police’s jurisdiction is up about 22% so far this year, according to stats provided by the department.