Jan. 2 (UPI) -- Detectives in Wyoming said they warned Colorado police about six weeks before a gunman shot dead a sheriff's deputy and wounded four other officers.
Detectives at the University of Wyoming in Laramie said they called and warned police that suspect Matthew Edward Riehl had emailed threats against professors at the school -- where he earned a law degree -- and showed signs of mental illness.
"These messages were highly indicative of someone with major mental health problems. It was definitely on the dark side of the spectrum," University of Wyoming Police Chief Mike Samp said. "Everybody knew Mr. Riehl could use some help."
However, Colorado authorities may have been unable to act on the tip.
"Wyoming statutes are pretty clear: If someone is not making an immediate threat, they cannot by held for a mental evaluation. They are very tough cases," Samp added.
Authorities say Riehl shot and killed Douglas County Deputy Zackari Parrish on Sunday.
Investigators said Riehl previously posted YouTube videos ranting about Douglas County, Colo., Sheriff Tony Spurlock and his office.
The shooting began after police responded to a disturbance call at the gunman's apartment complex in suburban Denver. Officials said more than 100 rounds were fired at officers.
The four injured officers were Deputies Michael Doyle, 28; Taylor Davis, 30; and Jeffrey Pelle, 32; and Castle Rock Police Department officer Tom O'Donnell, 41.
Two civilians were also hurt, although neither received major injuries.
"I am overwhelmed with by the love and support of the community and of the nation. Never in my world would I have imagined this," Parrish's wife, Gracie, said at a vigil Monday.
"I do will do everything in my power, Zack Parrish, to honor you," Gracie added. "And I will raise these girls to love you."