From oldguns.net I got this:
"# 1533 - Colt Army Special Revolver
11/28/98
Michael, Tulsa, OK, USA
Maker Model Caliber Barrel Length Finish Serial Number
Colt Revolver Army Special PTF (??) 32/20 6 Inch Blue 467291
Mfg. Hartford Pat. aug. 5, 1884 june 5, 1900 july 4, 1905 I would like a little history and approx. value of the gun. It is in good condition, but don't know if it can be safely fired. thanks
Answer:
Michael- over 240,000 Colt Model 1908 Army Special's were manufactured from 1908 to 1927, my records indicate that your revolver was manufactured in 1922. The Army Special was the successor to the New Army and Navy, and incorporated a number of improvements including modernization of the shape of the frame, cylinder rotation was changed to clockwise and the cylinder was locked by a single peripheral recess for each chamber, engaging with a bolt at the rear of the cylinder, the cylinder latch was rounded off, and the hammer was given a pivoting firing pin. Colt dropped the 3 inch barrel length, and lengths were standardized at 4.5 and 6 inches. Calibers included .32, .38 Short and Long, .38 S & W Special, .38 Special and .41 Long. Blue book values for the Army Special range from $175 to about $500 depending on condition and markings. It has been my experience that these are slow movers unless they have special markings, and I usually consider myself lucky if I sell one for over $175. As with any firearm this old, I would advise you to have it checked by a competent gunsmith before you fire it. Marc"
My guess would be that the "T.P.D. No. 344" means it belonged to some police department before.