Colorado gunman reportedly bought 11 guns from Wyoming store

The Colorado man who fatally shot a sheriff’s deputy and wounded six others Sunday in an “ambush-style” attack purchased 11 of his guns — including an AR-15 semiautomatic rifle — from a store in Wyoming, according to a report out Wednesday.

Matthew Riehl, an Iraq War veteran, was sold 11 guns from 2010 to 2013 from Dave’s Guns in Laramie, Fox 31 Denver reported, citing a police report.

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The store’s owner, David Smith, reportedly called Laramie police on New Year’s Eve, after Riehl’s shooting earlier in the day from his Highlands Ranch apartment, to tell authorities he sold the cop killer guns.

From April 2010 until March 2013, Riehl reportedly bought the AR-15, three semiautomatic pistols and one semiautomatic receiver, in addition to three revolvers, a shotgun, a pistol and a rifle.

Smith said Riehl passed all background checks at the time. Riehl apparently stopped purchasing guns from the store owner before he was hospitalized in a psych ward in 2014.

The gunman, who served in U.S. Army Reserves and Wyoming National Guard, allegedly livestreamed his attack, in which he fired off more than 100 rounds, leaving Douglas County Sheriff's Deputy Zackari Parrish dead. 

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Riehl graduated law school in Wyoming in 2011, and was honorably discharged from the Army in 2012. Within two years, he was hospitalized at a Veterans Affairs Department psych ward and, at one point, was placed on a 72-hour mental health hold.

It’s unclear if Riehl owned more than the 11 guns Smith sold him.

The Associated Press contributed to this report.

Nicole Darrah covers breaking and trending news for FoxNews.com. Follow her on Twitter @nicoledarrah.