The alleged shooter in a New Year's Eve mass shooting in Colorado was known to local police due to a reported history of alarming behavior.
Police say that Matthew Riehl, 37, was responsible for starting the incident that left one deputy dead and six others — including four deputies — injured in Highlands Ranch, Colorado, on Sunday. Police initially responded to the same apartment at around 3 a.m. Sunday in response to a noise disturbance call, but left when there was no noise after they arrived.
The officers came back to the apartment a second time around 5:25 a.m. in response to a domestic disturbance report, where they reportedly encountered Riehl, who had barricaded himself in his apartment, and allegedly began firing on deputies without provocation as they approached the apartment.
Five deputies and two civilians were wounded in the gunfire. One of the deputies' wounds were fatal. The deputy has been identified as Zackari Parrish, a 29-year-old father of two. Riehl was also shot and killed on the scene.
Police have not yet confirmed whether all of the injuries were caused by gunfire from Riehl, or if some of the injuries were caused by accidental gunfire from police as they attempted to contain the shooter. Over 100 total rounds were fired in the exchange.
What do we now know about the alleged shooter?
CNN reported that the Wyoming National Guard has confirmed that Riehl was a former national guardsman and Army reservist who had a one-year deployment in Iraq in 2009. Riehl was honorably discharged from the Army as an E-4 in 2012.
The Associated Press reported that Riehl posted a profane video on YouTube on Dec. 13 calling for Douglas County Sheriff Tony Spurlock to be fired. The rant attacks Spurlock in "highly personal terms" but does not offer much of a coherent explanation for Riehl's apparent animosity.
According to NBC News, Riehl also had a number of other Facebook posts and YouTube videos that expressed clear animosity toward members of the Douglas County Sheriffs office, calling them scumbags, dirtbags, and liars. In one of the videos, Riehl promised to run against Spurlock as a libertarian and "fire all those bums come early next year."
According to Spurlock, Riehl had "previous contacts" with Douglas County deputies, but had never been arrested and had no criminal record.
Still, police were aware of Riehl because of his interactions with various local institutions. Riehl was a 2010 graduate of the University of Wyoming School of Law, and in 2017, the school reported Riehl to campus police and Laramie Police Department in response to a series of "rambling, nonsensical messages on his Facebook page" about the school and that school officials were found to be "outrageous, vulgar, and alarming." Campus on security was heightened, and school officials were asked to alert police if Riehl was sighted on campus.