PHOENIX (3TV/CBS 5) -- It's the kind of case you'd see on a CSI show or a first 48-hour investigation.
Last week, a patient staying at a hospital in Phoenix was found dead moments after a visit from a mysterious person wearing a baseball cap.
Demetri Papamatheakis was close friends with the victim, Brandon Werner, a 41-year old Phoenix dad being treated for complications with diabetes.
"It almost sounds like something right out of the Sopranos," said Papamatheakis. "It's crazy. It's crazy."
Papamatheakis just spoke to Werner last Friday and says he sounded fine. Then, a few hours later he got the call that Werner was dead.
"It wasn't like this was a car accident or a surgery that went wrong," said Papamatheakis. "I mean, this is like we were all talking having a great time and all of a sudden he's gone."
According to Phoenix Police, a suspicious individual showed up at Honor Health's Deer Valley campus last Friday and told the staff he was there to visit Werner.
The man stopped in Werner's room, then left.
"The person did not stay very long," said Phoenix Police Detective Luis Samudio. "He's there for a short time, 15 minutes maximum, then he walks out. The nurse checks on the patient and sees that he's starting to become in distress."
Nurses reportedly found Werner foaming at the mouth and unresponsive. They did their best to save him, but it wasn't enough.
The search is now on to find whoever was in Werner's room to determine if they were responsible for the Phoenix dad's death.
"I just want to know answers," said Papamatheakis.
Friends describe Werner as a great guy, with a great sense of humor who was always there when you needed him.
A Facebook page is set up to help Werner's family with medical expenses.
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