==Massacre or Killing Spree? == 
 Should we refer to this incident as "Massacre" or a "Killing Spree"? 
 I think we should change the term "Killing spree" to "Massacre". A Massacre is "deliberately and violently kill (a large number of people)". Which is what the perpetrator did and how it has been described in the media:http://www.nbcnews.com/storyline/isla-vista-rampage/isla-vista-massacre-what-do-we-know-about-elliot-rodgers-n114416 It is also how it is described by Elliot Rodger himself. It was one incident. Spree killers usually span weeks: "that spree killers "will engage in the killing acts for days or weeks" http://en.wikipedia.org/wiki/Spree_killer Elliot killed his roommates on the same day he went to kill people in IV. 
 What do others think? I feel using "Killing Spree" is misrepresenting this event, especially that it lasted several weeks or days. It was ONE day. 
 :A massacre is committed by a group.    

 "Group" refers to the perpetuating party. In this case the party was Elliot Rodgers. Also the article you shared says:  and the perpetrating party is perceived as in total control of force while the victimized party is perceived as helpless or innocent.  Which is what happened in IV. 
 Killing Spree is incorrect because it refers to several days. The article on Killing Sprees names various individuals who committed a massacre. 
 The murders took place in ONE day not several weeks. What do others think? would it be OK if I change the term? Sorry about editing earlier I am a new female, who loves Wikipedia. I did not know the norms in detail. Thanks for the feedback. 
    
 :Where is it written that a spree must last several days?    

 In the article on killing spree it says: "Fuller and Hickey write that "[t]he element of time involved between murderous acts is primary in the differentiation of serial, mass, and spree murderers", later elaborating that spree killers "will engage in the killing acts for days or weeks" while the "methods of murder and types of victims vary". Andrew Cunanan is given as an example for spree killing, while Charles Whitman is mentioned in connection with mass murder, and Jeffrey Dahmer with serial killing"