DENVER -- Police say a former paramedic had a plot to kill his bosses at Denver Health Medical Center.
Court documents that were just released reveal investigators believe that man was just hours away from pulling the trigger on what could have been mass murder.
The documents show that in the fall of 2012, former Denver Health paramedic Matthew Mann hid in the bushes near the apartment of one of his supervisors.
Mann later told police he brought a rifle with him and waited for the man to appear in his bedroom window. Police called it a revenge murder the suspect never carried out.
On April 11, Mann allegedly confessed his plan to kill four of his former supervisors at Denver Health paramedics to a co-worker over text messages.
Some of them said the following:
"I've got (my supervisors' homes) scouted."
"I'm going to kill their children just to remove their DNA from the gene pool."
"I've spent nights outside their homes with them in the cross hairs, waiting."
The messages came in the middle of the night. A Denver Police SWAT team swarmed Denver Health and had it on lockdown by 7 a.m.
The court documents say Mann resigned from his job in 2012 after his supervisors threatened to fire him for driving recklessly and causing an accident. He was angry because he believed supervisors were treating him unfairly.
Stacy Harvey is a workplace threat assessment experts and she calls the threats in this case alarming.
"It's when they start planning and making direct threats that you need to take it seriously."
Police say Mann owned a gun shop in a strip mall in Centennial, and he owned more than 50 guns. They also say he scouted places in the mountains to escape to after the murders.
"You have a plan, you have access to guns and that's when it becomes serious," Harvey says.
It was so serious that Mann's wife eventually called police and arranged to turn him in.