Less than three weeks ahead of a presidential election expected to be one of the most contentious in American history, the Portland Police Bureau and Multnomah County Sheriff's Office announced Oct. 16 they will increase staffing on Election Day and for an unspecified amount of days following.

"In the past, some individuals and groups have gathered and marched following the election results, both in celebration and sometimes because they are angered or upset," the agencies said in a joint statement. "In some instances, significant damage was done to local businesses, which did not change the election outcome, but hurt our community members."

The agencies say they hope they don't have to make any arrests, but that they will not tolerate certain activities, including impeding transportation by blocking streets, vandalizing or damaging property, unlawful possession of weapons, and "assaultive behavior."

"This election season has increased fear and uncertainty for many of our community members," Portland Police Chief Chuck Lovell said. "We ask for the public to help us by reporting criminal activity, staying informed, and engaging in lawful activities. Together, we can achieve a safe election season in Portland."

The staffing decision appears to be prompted by the nightly marches that blocked Portland freeways for seven consecutive nights in 2016 after the election of President Donald Trump, and the more than 100 days of protests against police brutality this summer, which turned into a standoff with federal officers deployed by Trump.

The agencies say they support people's First Amendment rights, and that the decision to increase staffing on Election Day and the days following is precautionary.

"Safe elections are critical to a healthy democracy," Multnomah County Sheriff Mike Rees said. "The Multnomah County Sheriff's Office is dedicated to ensuring community members can safely exercise their right to vote and peacefully gather to engage in free speech events."