Here is an interesting scenario to ponder....In the episode "measure of a man", Picard and Data go all out to defend the idea that an android has rights and ought to be treated like any human with regards to the law. If that is so, then how do we explain what happened to Lore?
Lore committed heinous crimes and was captured by Data. He was incapacited, and instead of arresting him and putting him on trial for his multiple counts of conspiracy and murder, the Enterprise crew just deactivate him and, presumably, disassemble him. Is this a terrible example of hypocrisy on the part of Picard and Data? Are androids only people so long as they are good?
Nope.... Data and Picard were responsible for re-activating him and unleashing him on the galaxy..... he attempted to kill the entire Enterprise crew, he wiped out an entire colony, both by using the Crystal Entity, he killed his creator/father, he took over Borg for his own personal gains of enslaving organics and conducted tests on borg and humans for his own sick amusement.
Considering that there's no real known way of restraining an android or keeping them behind a force field ala a prison due to their strength and abilities to use components from their body to manipulate technology to their advantage (thus escape) and he has continually shown that he doesn't give two craps about society, laws, morals, etc..... the only logical course of action was to deactivate him and disassemble him..... which wouldn't be much different from some lunatic attempting to kill a bunch of people or torturing them and the only option was to put a sniper bullet between their eyes since they would never surrender.
Actually considering they said they only deactivated him and disassembled him, he's not actually dead, since he could always be put back together and turned back on.
The simplest answer is that you'd never be able to put him on trial or send him off to jail, let alone send him to some penal colony in New Zealand to dig ditches, without him either trying to escape or attempting to kill anybody near him.
The Argument that Data was in the wrong and he violated his rights is a bit weak considering when you break the law, you lose certain rights..... Lore was a mass murderer and there was no way to reason, let alone confine him in any means of punishment that would ensure the security of anybody near him or give justice to his victims.
It seems a tad screwed up to play Lore as the Victim compared to all the things he did and his very last physical action was to attempt to kill Data.... Data did exactly what was necessary and logical based on the given situation and could be argued his actions were in self defence of not just himself but everyone else.
Chances are, the logical course of action was to deactivate him and disassemble him for the time being until they know of a way to properly confine him in a safe manner and find a proper punishment for his crimes.