Magento call observer after customer delete : You can call observer after customer delete in magento as below.
Syntax of Magento call observer after customer delete
Add the following lines of code in your config.xml with details of your module.
<events>
<customer_delete_commit_after>
<observers>
<observers>
<namespace_modulename_model_observer>
<type>singleton</type>
<class>Namespace_ModuleName_Model_Observer</class>
<method>Name_of_method</method>
</namespace_modulename_model_observer>
</observers>
</observers>
</customer_delete_commit_after>
</events>