Well, I have one for you people-
A group of four friends (Sherlock, Mycroft, Irene and John) went out to dine in a hotel on the occasion of Sherlock getting a job. When they were having dinner together, they were deciding on a nightly walk outside the hotel. However, John (Sherlock's best friend), refused as he was expecting a call from one of his mates on a reply from a job agency. The rest three decided to go anyway.
On the last minute, Sherlock too refused with an account of an upset stomach. So finally, only Mycroft (Sherlock's brother) and Irene (Sherlock's ex) went for the walk. As they were right about to leave the hotel, Irene excused herself to the bathroom and came back a bit late. Mycroft waited for her at the hotel exit gate.
By the time they came back, Mycroft found Sherlock shot dead in his room.
On investigation, the following points about the scene-of-crime were noticed-
Sherlock was found shot at his right temple, in the room's toilet
The gun used (no silencer) was found inside a bag belonging to Mycroft
On questioning, the following facts came out
MYCROFT HOLMES (BIOLOGICAL SIBLING OF DECEASED)
Was sharing the room with the deceased
With no solid alibi, he claims to be waiting at the hotel exit gate for Irene
When she took more than ten minutes, he called her on her mobile
Embarrassed, Irene answered that she will be out in a minute. Mycroft heard her flush the toilet on the phone.
He says he did not hear a gunshot. However, agrees to be in possession of a gun.
IDENTIFIED MOTIVE: Deceased was the cause of the death of Mycroft's wife
2. JOHN WATSON (ACQUAINTANCE OF THE DECEASED)
Had a private room two rooms next to the deceased's room
Was allegedly talking to a third party individual on mobile regarding employment hunting
The third party confirms the conversation, call log on mobile double checks.
Claims to never have left his room. Accepts hearing gunshot but ignored it. Accepts to be in possession of a gun.
The third party also says it heard hurried footsteps on the phone
IDENTIFIED MOTIVE: Deceased had, at the expense of John, got his new job by bribery
3. IRENE ADLER (EX-GIRLFRIEND OF DECEASED)
Had a private room right next to the deceased's and John's room.
Agrees with the movements described by Mycroft Holmes
Agrees to have heard the gunshot and also heard someone rush past her door before leaving the room to catch up with Mycroft. Too had ignored the gunshot as a crashed hotel cart. Accepts to be in possession of a gun.
IDENTIFIED MOTIVE: The relationship between the deceased and Irene ended due to the deceased unable to solve a case in time costing the life of her brother Godfrey Norton.
These accounts are sufficient to catch the murderer. With right reason, explain who the murderer is.
FUN FACT: The previously mentioned Godfrey Norton is the fictional husband of Irene Adler she eloped with in Sir Doyle's short story 'A Scandal In Bohemia'.