The schoolboy had waved goodbye to a friend on November 23 as they walked back from Birkdale High School, but he never made it to the family home just a few streets away in Pennine Road, Earlsheaton.
He had been strangled with his own tie and sexually assaulted by serial sex offender Richard Mortimer, an unemployed 37-year-old man who had previously lived in Belvedere Mount, Beeston.
But it would be more than seven weeks until killer Mortimer entered the Park Hotel in Earlsheaton and prompted the suspicious landlord to call police.
In the intervening weeks, officers had staged a reconstruction with the help of a local 12-year-old boy and interviewed more than 2,000 people.
Meanwhile, Mortimer had dumped some of Steven’s belongings in a skip in Dewsbury and stuffed the tie into a toilet in public facilities in the town.
He had also shaved off his beard, moved lodgings, assumed a false name and been homeless for a while.
When he turned up at St George’s Crypt in Leeds on November 25 and asked for soup, he gave the name of Richard Howard.
After being interviewed by police in January 1983, Mortimer was charged with Steven’s murder.
He finally admitted his crimes part way through the trial in October that year, telling the court he had not intended to kill Steven and was “terribly sorry”.
Jailing him, Mr Justice Glidewell said: “Words are quite inadequate to describe the horror of this particular offence. No right-minded member of the public can view what you did with [anything] other than detestation.”
He said he would recommend that Mortimer serve a minimum of 16 years because the killing and his previous record suggested was a danger to young boys.
The court he had been jailed in June 1965 for four years for rape, aiding and abetting rape, and assault occasioning actual bodily harm.
He was then jailed for three years in August 1978 for abduction, indecent assault and indecency with a boy of 10.
The court also heard there was a warrant out for his arrest at that time in relation to an assault on a six-year-old girl.