Senior Liberal Democrats have not entered the row which has seen David Cameron back Chancellor George Osborne's comments that the case prompted "wider questions about our welfare system."
Mr Alexander said: "The Philpott case is an individual tragedy. Children have died in that case.
"I think that is where we should let that case lie. I would not want to connect that to the much wider need to reform our welfare system."
More top news
UK airport passengers have to walk up to a kilometer from check-in desks to reach their departure gates, new research has shown.
In an annual survey taken among local authorities in the UK, 2,463 stray dogs were put to sleep between April 2015 and March 2016.
Inspectors found the availability of drugs at HMP Bedford was having a "serious impact" on safety.