Since you are asking this in the Washington forum and you list your location as Seattle, I will be happy to provide an answer that might actually be useful to you.
Originally Posted by ironmike86
In Washington State, in addition to the Federal Form 4473, there is a Washington State Pistol Transfer Form. With a Washington CPL, the CPL number is recorded on the Washington State Pistol Transfer form and the five day waiting period is waived. Without a CPL, the Pistol Transfer Form is sent to the local LEO agency and they do an additional background check in addition to NICS, including medical records, hence the 5 day waiting period.
Whether or not you use your CPL, the Washington State Pistol Transfer Form is sent to the Department of Licensing who then enters the sale in their database so that they can cross reference the serial number of the gun you bought with all of your personal information, driver's license number, and CPL number. By giving one piece of information, a LEO can get all the other pieces: for example, he can inquire about a serial number from a pistol and the Department of Licensing will instantly tell him who bought the pistol, their address, what their driver's license number was used to purchase the pistol, and CPL number if used.
This applies only to handguns purchased from FFLs, although the form can be OPTIONALLY completed and sent in for private party sales.
The applicable RCWs are 9.41.090 and 9.41.129. A Washington CPL does NOT exempt you from the Federal NICS check.
Anyone who says, "I support the 2nd amendment, BUT"... doesn't. Element of Surprise: a mythical element that many believe has the same affect upon criminals that Kryptonite has upon Superman.