There is a set of specialized words that is used almost entirely by the Funeral industry professionals. They are slowly creeping into more common use, but still sound very formal. "the Deceased" is one of these words. Also "the bereaved" referring to the family. "Remains" meaning the dead body. "The late" is always followed by the person's name, "The late Mr. Smith" It implies that the person died somewhat recently (up to maybe 5 years). It's not used for people who died a long time ago. You see this more in written English than spoken English. In spoken (American southern) English we normally just use the past tense verbs but otherwise talk about the person as if they are still here.

It would be unusual to note the death of a person grammatically when speaking to the family of that person - you can be sure that they already know. So these terms are used solely for informing, gently, that the person of whom you speak, is deceased, it is redundant, and insensitvely so. If we are being very gentle about saying it, and perhaps when we would rather not mention by name the people we speak of, we often refer to those who have left us as 'the departed'. For example, when addressing a group of people, perhaps praying for a number of deceased people, we can collectively refer to them as 'the departed' or 'the dearly departed' Clair is correct, the Deceased is very formal. 'The late Mr Smith' is a polite way to speak of someone who has recently passed away. A widow may sometimes refer to 'my late husband', and could do so for decades after he died. Sometimes you will see 'late' used this way: 'Mr Smith, late of Jakarta'. It is an odd phrasing, which you might see in a media report. It means 'the person, Mr. Smith, who recently died, was from Jakarta'. When the person died a long time ago, we can be more frank. 'Mr smith, who passed away in 1990...' or 'Mr Smith, who died in 1990 when his car...

Both are exceptable but personally I would use "the late". You tend to hear "the deceased" in very formal circumstances, for example, the reading of a will or in a court case which is concerned with the death of someone.

Interests me since 1969 when by chance I met Latif La, in Peshawar court room. He was composing a job application for a person and when done he looked to me saying 'oh you Mr. Mohammad, want me to write one for you too? I said no I just was around and seeing you wanted say ha! But he said no let me do it for you too as many new jobs are around in civil secretariat. I knew that because of revival of province many young chaps were around keeping him busy. He was my friend but I knew that being in grade 12 I got to study two more years of schooling...Any way he did it and at the end putting my name in the old Indian tradition he mentioned my father's name as deceased so and so! Done with it handing me the page I saw that Mr. Abdul Halim Advocate emerged into the room. He was our family friend so asked me hurriedly as what was I after in court premises. Then he took the page from my hand and read it hurriedly saying Your father was not killed but died his own death...mentioning that deceased means the one got killed! This erupted a discussion between both the advocates. Another Attorney more senior to both intervened saying that deceased means dead for longer years while Late is comparatively a recent happening! Upon this I being grade 12 student interrupted them saying but Late news was not dead news but the most fresh one! So, they laughed saying well then tell us what is the fresh news that you have now? I said he late news is this that I'm not looking for job now for being a grade 12 student...This made the senior most present utter that kid do it now or two years later be too late for you to find a job...