Patil was speaking at the inauguration function of a police training centre building in Turchi of Sangli district.
"Once Mumbai police was known to be among the top police forces in the world. But now, what is the condition? Is there a shortcoming in the machinery, training or willpower?" the minister asked.
"The conviction rate is just eight per cent. That means, ninety two per cent people go scot free," he added.
"The investigating officers should put up such a strong case (against the culprits) that even a judge does not find it easy to grant bail," the BJP leader said.
Chief Minister Devendra Fadnavis holds the Home portfolio.