"When I Hit 22, I Stopped Counting,"

Well, she apparently only needed to count 1 more before being caught.
From the Chicago Tribune: The FBI said on Sunday it was in contact with local police in the case of Miranda Barbour, who is charged with murdering a Pennsylvania man she lured via the website Craigslist and reportedly admits to the killing and at least 22 other slayings.
Barbour, 19, could face the death penalty in connection with the murder of the 42-year-old man who answered her bogus ad offering sex for $100, authorities said.
In a jailhouse interview, Barbour said she was part of a satanic cult and had no remorse for her victims, according to an article published in Saturday's edition of the Daily Item newspaper in Sunbury, Pennsylvania.
She admitted that she and her husband stabbed and strangled Troy LaFerrara in Sunbury in November because "he said the wrong things."
Barbour also said she had killed at least 22 people in different parts of the country, including Alaska, California, Texas and North Carolina.
"When I hit 22, I stopped counting," she said in the article on the paper's website.
"I can pinpoint on a map where you can find them," she said.
The FBI said on Sunday in a statement that its Philadelphia division "has recently been in contact with the Sunbury Police Department regarding Miranda Barbour, and will offer any assistance requested in the case."
http://www.chicagotribune.com/news/sns-rt-us-usa-crime-barbours-20140215,0,7082592.story
My guess is that this is a planned strategy for a mental illness defense instead of being a tale of a murderous tramp.