Bowman is accused of gunning down Noll, 42, in cold blood on Aug. 31 when he pulled up opposite him in his silver BMW at a North Seattle intersection, possibly after a road rage incident.
Now prosecutors say that video of Bowman at a pistol shooting competition in Puyallup may become an important piece of evidence in the case. It shows that he is an excellent shot - hitting one target after another in rapid-fire succession.
"One-handed, firing at a series of targets, hitting every one of them square on ... both right-handed and left-handed," says W. Scott O'Toole of the King County Prosecutor's Office.
Bowman was arrested Friday after police received an anonymous tip from someone who said Bowman matched the description of the suspect in the killing and that he drove a silver BMW like the one seen in surveillance video on the day of the shooting.
Investigators say at least three bullets hit Noll in the head. He died at the scene while seated behind the wheel of his car at NE 75th and 15th Avenue NE.
A judge has ordered Bowman held in the King County Jail without bail.
"There's a concern that somebody who could even, if impulsive, could act this way, presents a danger to the community," says O'Toole.
Police tell KOMO News they found a so-called "gun room" during Friday's search of Bowman's home, filled with bullet-making equipment, ammunition and rifles. They also found evidence he owns at least one handgun.
A safety officer at the Puyallup gun range confirmed the video of the shooting competition was taken at his facility, but does not remember Bowman - and does not recognize him as a member of the gun club.
Prosecutors say they believe the video helps confirm in their minds that they've got the right man.
"It shows his interest and proficiency with weapons, what we believe is consistent with the person who committed the murder of Yancy Noll," says O'Toole.
Court documents also say the passenger window appeared to have been replaced on Bowman's BMW and new tires put on the car, but that fragments of shattered glass were found in the vehicle and the garage.
Prosecutors expect to file murder charges against Bowman by Tuesday.