DENVER (CBS4) – The CBS show “48 Hours” will focus on a disturbing Colorado case this weekend.

Marc O’Leary pleaded guilty in 2011 to raping women in Golden and Westminster and was sentenced to 327.5 years for the rapes, as well as an attempted assault in Aurora. He also faced charges in the state of Washington.

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Marc O'Leary (credit: Jefferson County)

Marc O’Leary (credit: Jefferson County)

Investigators said O’Leary planned his attacks, staked out four victims in Colorado, assaulted them repeatedly over several hours and then took methodical steps to make sure no evidence was left behind.

The 48 Hours episode includes interviews with detectives — Stacy Galbraith and Edna Hendershot — who worked on the case and knew O’Leary was continuing to prey on more victims as they conducted their investigation.

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“They knew they had somebody out there who was extremely calculating, who was really playing a game of how not to get caught. Taking every piece of evidence and also making sure that he was not committing the crimes in the same area,” said Maureen Maher of 48 Hours.

“He would constantly be going to different cities so that the different municipalities wouldn’t know who had which evidence and wouldn’t be able to connect the dots.”

FBI Special Agent Jonny Grusing also is featured on the episode.

Grusing told 48 Hours he was surprised during the course of the investigation “to see a suspect who was so cunning in not getting caught.”

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Watch the show on CBS4 at 9 p.m on Saturday.