Sometimes referred to as the “Beast of Chicago,” Holmes is believed to have killed somewhere between 20 and 200 people.

Despite Holmes' confession of killing 27 other people (some of those people were later discovered to be alive and well), he was officially linked to nine murders. Some estimate Holmes had killed up to 200 people, but these claims were exaggerated.

The official number is 27; according to a recent profile of the serial killer in Rolling Stone, this is the number of victims that Holmes confessed to murdering after his arrest.

Linking Holmes to their murders, police arrested him and he was convicted of their murders. He also confessed to 28 other murders; however, through investigations and missing person’s reports, it is believe that Holmes is responsible for up to 200 murders.

So is his death count: Police at the time suspected around nine or 10 victims, while other estimates are in the hundreds; in his published confession, Holmes himself claimed credit for the deaths of 27 people—but several “victims” were later found to still be alive.