PHOENIX -- Detectives hit the streets Friday, going door to door to drum up leads in Wednesday night's church attack that left one priest dead and another critically injured.
So far, the only description of the suspect is that he is a white man in his 40s.
"These types of crimes where we have very little to go on, many times Silent Witness is what solves these crimes," said Silent Witness Coordinator Sgt. Darren Burch.
The crime was brutal.
Two priests, the Rev. Kenneth Walker and the Rev. Joseph Terra, were attacked at their living quarters, a small building attached to the Mother of Mercy Mission Church in downtown Phoenix.
Police say Terra, 56, was beaten. Walker, 28, was shot and later died from his injuries.
"When I heard the details I was deeply saddened," said parishioner Daniel Spiotta.
While the suspect description is vague, there are other details police have been able to piece together.
"This individual is probably a very violent individual," Burch said. "We've probably seen this type of action in his past."
Given the violent nature of the attack, officers say, at this point, every theory is on the table, from a crime of opportunity committed by someone high on drugs to something much more personal.
"Could it have been targeted against this church, against these priests? It could have been. We can't exclude anything," Burch said.
That is why Silent Witness is asking for more tips, so that they can narrow the realm of possibilities.
"We're hoping the community will now come forward and give us a direction," Burch said.