What is the ruling on praying over a deceased person whose state of Islam is unknown?

Prayer is offered for a Muslim, whether righteous or wicked. If the deceased was known to be Muslim but their adherence to Islamic rituals was obscure, the default is that they are Muslim, and prayer is offered for them. Muslims have unanimously agreed that it is not permissible to abandon prayer for sinful Muslims. If someone dies in Muslim lands and their condition is unknown, but signs of Islam are apparent on them, prayer is offered for them due to the concordance of the apparent with the default. However, if signs of disbelief are found on them, there is a difference of opinion among scholars regarding praying for them. If someone dies in non-Muslim lands and signs of Islam are found on them, prayer is offered for them, acting upon the apparent.