Skip to main content

Main menu

  • Shows
  • News
  • Schedule
  • More
    • All
    • More
    • Watch Live TV
    • Channel Finder
    • Oxygen Insider
    • Snapped Podcast
    • Shop Oxygen
    • Peacock
    • Advertise With Us
Sign Up / Log In
Manage Profile
Email Preferences
Sign Out
Create your free profile and get access to exclusive content.
Sign Up / Log In
Link your TV provider to stream full episodes and live TV.
Markofaserialkiller S3 Web Dynamiclead Desktop 1920x1080
Saturdays at 8/7c

Mark of a Serial Killer

What is left behind is a trademark clue that ultimately aids the investigation in stopping these murders and bringing the killer to justice.
Watch S1 E1 Watch in the App

  • Home
  • Watch
  • News
Season 1Season 2Season 3
Full EpisodesClips & Playlists
The I-95 Killer
43:49
S3 - E2

The I-95 Killer

The Charmer
43:49
S3 - E3

The Charmer

The Englewood Killer
43:31
S3 - E4

The Englewood Killer

Classified to Kill
43:49
S3 - E5

Classified to Kill

The Monster
43:54
S3 - E11

The Monster

The Bayou Strangler
43:54
S3 - E12

The Bayou Strangler

The Skull Crusher
43:54
S3 - E13

The Skull Crusher

The DC Sniper
43:54
S3 - E14

The DC Sniper

Become an Oxygen Insider

Get an all-access pass to never-before-seen content, free digital evidence kits, and much more!

Sign Up for Free

Oxygen Insider Exclusives

Check out never-before-seen content, free digital evidence kits, and much more!

See Insider Exclusives
  • About
    • Careers
    • Viewer's Voice
    • Advertise with Us
    • Contact
  • Help
    • FAQ
    • Closed Captioning
    • Shopping Support
    • Sitemap
    • Crime News RSS
  • Policies
    • Ad Choices
    • Privacy Policy
    • Your Privacy Choice
    • CA Notice
    • Terms of Service

Stay Connected

Facebook Twitter YouTube Instagram
©2023 Oxygen Media, LLC. A Division of NBCUniversal