I'm guessing your from the UK since this takes place on a double decker bus, so I'm clueless when it comes to the layout of the upper deck, but, I'm assuming that when you say the drunks are in the back of the top deck, they are above the rear wheels with the driver and the gun over the front wheel area. Wouldn't Columbo, as seen in "Now You See Him", be able to deduce that the shot came from the front of the bus and not the back and upon inspecting the front area of the bus, find something to indicate that a weapon had been mounted there with a hole drilled down to the driver's area? I'm guessing someone who's constantly drunk wouldn't keep a receipt for a gun so I doubt Columbo would ask about it and assuming that the gun was untraceable, that may be a dead end. If Columbo suspected the driver, and after a ballistics test proved that the gun the drunk had wasn't the murder weapon, but that it had been fired, he may start poking around the driver's home hoping that he could find where the gun was fired and hopefully recover the bullet, similar to "The Greenhouse Jungle". But, if the driver actually got rid of the actual murder weapon, Columbo may have to force him to incriminate himself or manufacture eveidence that forces a confession.

Correct, the drunks are at the rear end of the bus, however the bus driver's suggestion is that the drunk went up from the back of the bus to the front and then shot him, before backing away. None of the drunks can really argue this as they were all too drunk to remember what happened that evening, so the police just had to take Harry's word for it. As for the area the gun was mounted, there was really nothing to suggest it was ever there. No hole needed to be drilled because at those times busses were built in with an opening above the driver so that they could see into a mirror. He wiped the area with a damp cloth, too... however, it is possible some gunpowder fell down unto the driver as well as no his seat and dashboard. If there somehow was a reason for him not to clean all of it, there would be incriminating evidence for Columbo to find.

The gun would have been fired into a cushion and into the ground in his bedroom, and he then would have pushed his wardrobe over the bullethole it left it hide it. Colombo would need a warrant to move it. Unless he can provide a substantial reason to the police as to why there could be a bullethole under there, I agree, he would probably either need to get him to trip himself up somehow or force a confession.

He'd solve it in ten minutes I'm afraid.. And that's assuming it was carried out successfully which is extremely unlikely.
The drunks even in their state would be able to say that the shot came from the front of the bus and none of them were there. Columbo would look at the front and see the hole and the mirror.
There would no drunks' fingerprints on the gun at all.
The shot would have to be bang on target to kill and not just to wound. Harry would find it near impossible to negotiate driving a big bus and shooting the gun on target through a mirror.
With a few tweaks this might get into a script consultation for an episode but I don't think it would get past that.

It sounds interesting. You should flesh it out and publish it on the fanfic site. I really enjoyed those stories.

Just a reminder - There are only a few of us who use the forum. We do not use language like that even if it is disguised. That might be acceptable on MTV or YOu Tube sites but not here. Obviously no harm was meant but lets keep the language here mature and respectful. Thanks.

I just checked what I wrote and wonder about your reply. I thought I sounded civil, maybe a bit preachy, and I stand by what I said. It was not a personal attack, just a reminder. Your reply was ... well, what can I say. But lets end it at that and spare the great users of this forum.

However, if you did not mean ****ty when you wrote ****e, I apologize.