According to various sources, MO evolves over time. It is always improving as the criminal learns better ways to do things to avoid being caught. This raises the idea that the MO of the intruder had evolved to the point where he was able to enter a house undetected, subdue and move a child to a remote area of the house, and commit his crime without disturbing the other occupants. The long ransom note was handwritten using items found within the home. The note would prove untraceable. The note indicated a phone call could be expected, but the phone call would never come, and could therefore not be traced. While there may be DNA in criminal places, there are no fingerprints. The DNA is not traced to anyone. The cord and tape cannot be traced. Truely a criminal feat. Evidence but no traceability. The cost of the murder weapon? $2.29 http://www.crimeandclues.com/92feb003.html Violent Crime Scene Analysis: Modus Operandi, Signature, and Staging By John E. Douglas, Ed.D. Special Agent Chief of the Investigative Support Unit FBI Academy and Corinne Munn Served as Honors Intern FBI Academy This Article Originally Appeared in the FBI Law Enforcement Bulletin, February 1992. [Excerpt] Unfortunately, investigators make a serious error by placing too much significance on the M.O. when linking crimes. For example, a novice burglar shatters a locked basement window to gain access to a house. Fearing that the sound of a window breaking will attract attention, he rushes in his search for valuables. Later, during subsequent crimes, he brings tools to force open locks, which will minimize the noise. This allows him more time to commit the crimes and to obtain a more profitable haul. As shown, the burglar refined his breaking-and-entering techniques to lower the risk of apprehension and to increase profits. This demonstrates that the M.O. is a learned behavior that is dynamic and malleable. Developed over time, the M.O. continuously evolves as offenders gain experience and confidence. Incarceration usually impacts on the future M.O.s of offenders, especially career criminals. Offenders refine their M.O.s as they learn from the mistakes that lead to their arrests. The victim's response also significantly influences the evolution of the M.O. If a rapist has problems controlling a victim, he will modify the M.O. to accommodate resistance. He may use duct tape, other ligatures, or a weapon on the victim. Or, he may blitz the victim and immediately incapacitate her. If such measures are ineffective, he may resort to greater violence or he may kill the victim. Thus, offenders continually reshape their M.O. to meet the demands of the crime.