I have "William Brooks" Newton Ks. Marshall badge, presented after a gun fight in which he was shot 3 times and killed 3 Texans.  He was also a lawman in Dodge City and several other locations.  Later he was lynched by vigilaties for horse theft.  A very colorful well documented character in Kansas.  Badge was verified at Antiques Roadshow in Omaha Nebraska in 2015, for time period correctness, they valued badge between $4000.00 and $8000.00 .  I have quite a bit of documentation on Brooks, easy to Google...A very nice piece for the collector... Serious inquiries only.   Negotiable....