Kamran Ghafoor discovered the damage at about 02:00 BST after attending a vote count.
People living in all 10 boroughs of Greater Manchester will head to the polls on Thursday 7 May.
Amanda Shelley says attending Chadderton Hall Park centre has changed her brother's life.
Derker in Oldham had seen five shootings in two months before a major police operation was launched.
Greater Manchester Mayor Andy Burnham says "the time has come to let this inquiry do its business".
A safeguarding review finds there were "missed opportunities" to pick up the child's neglect.
Oldham Council says the "deeply distressing" case has led to an overhaul of safeguarding policies.
Oldham Council says public money would have to be used to clean-up the illicit graffiti.
The visitors centre will open at the Northern Roots regeneration project next year.
