I am no lawyer and all the facts I quote are from my memory and reported in the press at the time. However I leave to fellow N/lnders and lawyers in the house to comment.
Any unlawful killing is murder

Bernard Ogedengbe, Bartholomew Owoh and Lawal Ojulope were convicted in August 1984 for their involvement in trafficking hard drugs outside Nigeria. At the time the only penalty for drug trafficking in Nigeria was regarding misuse of the pharmaceuticals, etc which had a maximum penalty of something like 6 months imprisonment.  Supreme Military Council felt this was too lenient and examples must be made. The SMC decreed (perhaps with advice of the legal advisers) to change the law and allow for death by firing squad to convicted drug pushers. 

However here's the problem. the SMC led by Buhari backdated the decree to 31st December 1983 when they took over power (by force) but the offences were committed prior to August 1983 when Buhari and co were mere soldiers doing their supposed jobs guarding the country.

So these three were found guilty and killed by firing squad in their local communities, I remember,Ogedengbe, a regular Warri/Sapele boy was killed in Sapele.

My question is these 3 were Killed not only by a law that was retroactive but worse still the law did not apply to them because the law started Dec 1983 after the offences were committed, even by Buhari standards they were killed unlawfully. Unlawful killing equals murder - should Buhari be tried for murder, he signed the death warrant.

Nigerians. . .over to you.
I ain't even looking in his direction for he does not exist in my books.

What hope do we have when the aspirants to lead the country all have massive holes in their character, I really pity those who seek to praise Buhari, Atiku, Jonathan as if they are messiahs.

Buhari led this country by dictate, he didn't need NASS, political parties, pressure groups, he ignored or locked up the press and with no opposition what good did he do? flog people in the street in name of war against indiscipline, kill people in the name of oppressive laws, we used to queue for hours to buy your allocation of 'Omo', sugar and toilet roll (the term essential commodity was invented), foreign exchange for our industries was diverted to connected people, whilst Fela was arrested and jailed for having a few hundred dollars on his person.

let anyone show me one legacy of Buhari as head of state or even head of PTF

The killing of those young men was terrible wickedness.

Absolutely.  Ayatollah Buhari MUST one day be handcuffed and led before the same tribunal in The Hague that sentenced former Liberian warlord Charles Taylor to a good stretch of hard time behind bars.  Both of these madmen are guilty of crimes against humanity, and both, in the fullness of time, should be made to pay, and pay dearly.

Buhari's continued freedom to ululate about his insane compulsion to forcibly convert Nigeria into an Islamic backwater is a continuing travesty of justice, considering the sheer volume of blood on the hands of that former tyrant who murdered so many of the innocents he tossed into dungeons with a smirk, during his reign of terror in the early 1980s.