Definition: Generate an appropriate title for the given text. The generated title must be short and include the main topic of the text. The preferred titles are under fifteen words.
Input: Staff and visitors restrained a man who allegedly scratched the work, known as The Morning Walk, with a sharp object. The gallery said the scratches had penetrated the paint layers but not torn through the canvas. The Metropolitan Police said Keith Gregory, 63, of no fixed address, had been charged over the attack. The gallery said a visitor had allegedly attacked the painting in room 34 of the east wing with a sharp instrument at about 14:15 GMT on Saturday. Gallery assistants and visitors detained him before he was arrested by the Metropolitan Police, according to the gallery. The east wing of the gallery was evacuated and closed for two hours, and the 1785 painting, officially titled Mr and Mrs William Hallett, was removed from display. "The damage is limited to two long scratches which have penetrated the paint layers, but not the supporting canvas," a spokesperson said in a statement. Conservators will now decide how best to preserve the painting, the gallery said. One Reddit user described the scene just after the attack: "One of the staff shouted at everyone to move aside. An older man, surrounded by about 6-8 staff, was quickly taken past us." The poster said onlookers believed the alleged attacker had used a screwdriver. A Metropolitan Police spokesperson said that Keith Gregory was charged on Sunday with causing criminal damage to a painting at the National Gallery the previous day. He was remanded in custody to appear at Westminster Magistrates Court on Monday.

Man charged with damaging National Gallery masterpiece