Seattle homicide detectives haven't found the 9-mm handgun that was used to kill motorist Yancy Noll at a North Seattle intersection on Aug. 31, but they did find a slide along with empty holsters and magazines for a 9-mm handgun in the workshop and home of the suspected gunman, according to King County prosecutors.

Dinh Bowman, 29, was charged Tuesday with first-degree murder, accused of pulling his silver BMW Z4 convertible alongside Noll's vehicle at a stoplight and firing five times, striking the 43-year-old three times in the head, according to charging documents. A 9-mm bullet casing was found next to Noll's car, an expended bullet was found in his dashboard and another bullet, shot through a window, was found inside a nearby house, the papers say.

Bowman was arrested Friday and is being held without bail in the King County Jail.

An anonymous tipster who called the Seattle Police Department's homicide unit on Sept. 12 apparently gave detectives key information they needed to make the arrest. The caller had seen a Crime Stoppers bulletin, featuring a sketch of the gunman's profile that was created from witness descriptions, according to charging documents.

The caller provided Bowman's name and address, said he had anger-management issues, drove a silver BMW and likely possessed a gun, the papers say. The caller also told a detective that Bowman "might be capable of committing such a crime," charging papers say.

Bowman's house is just over a half-mile from the intersection of 15th Avenue Northeast and Northeast 75th Street, where Noll, a wine steward at the Capitol Hill QFC, was shot.

Police records and Facebook offered more clues: Bowman had a concealed-weapons permit and a registered .40-caliber Glock, charging papers say. Photos posted on Bowman's wife's Facebook page showed a photo of Bowman in profile which "is strikingly similar to the composite sketch of the suspect," the papers say.

A second photo on her page "shows Bowman wearing large sunglasses" like the ones in the police sketch, charging papers say.

After receiving the tip, detectives knocked on Bowman's door, noting a home-security surveillance camera mounted to have a view of the porch, the papers say. No one answered, and on the next day detectives began a weeklong stakeout, according to charging papers.

Police determined that Bowman's wife drove a Mercedes-Benz C230 and one evening, as it was being pulled into the garage, the car's taillights provided enough illumination for detectives to make out "the outline of a light colored vehicle with a low profile" inside, the papers say.

Police got a warrant to search the garage, then additional warrants to search Bowman's residence and a Sodo workshop, the headquarters of Vague Industries, where Bowman apparently manufactured some kind of robotic equipment, charging papers say.

They found Bowman's BMW Z4 in the garage of his home, the papers say. He allegedly had replaced glass that had been shot out of the passenger-side window and changed and painted all four tires in an apparent attempt to conceal the crime, charging papers say.

Detectives also found a "gun room" in which "Bowman had set up a sort of laboratory dedicated to his obsession with guns," including bullet-making equipment, ammunition, long rifles and scopes, the papers say. While no handguns were found, detectives "did locate two empty 9-mm holsters and magazines," the papers say.

At Vague Industries, detectives found the tires Bowman had taken off his BMW — the treads matched skid marks at the shooting scene — and also located a slide for a 9-mm handgun, according to charging papers.

"This item was concealed in a plastic container, wrapped in paper towels and placed on a shelf in the back of the shop," the charging papers say in reference to the slide.

Bowman's wife was interviewed by detectives and gave consent for them to search her purse, charging papers say.

She claimed that the BMW passenger-side window was shattered while she and her husband lunched in Portland and that they had the window replaced at a repair shop there, the papers say. Detectives found a receipt in her purse for four new tires purchased from a tire store in Lynnwood, along with a Home Depot receipt, dated Sept. 12, for masking tape, masking paper, steel wool, gray primer paint and black spray paint, charging papers say.

When asked if Bowman's wife could face charges, Dan Donohoe, spokesman for King County Prosecutor Dan Satterberg, said detectives are still investigating her "with regard to her possible actions after the fact."

Sara Jean Green: 206-515-5654 or sgreen@seattletimes.com