He will be sentenced to death.
He warned Magwitch not to return to England, as that would constitute a felony and, if caught, he would be hanged.
Abel Magwitch had been using the alias "Provis" since coming to England to hide his true identity.
The prisoner Provis/Magwitch had been transported (shipped to Australia as punishment for a crime) for a stated number of years. He returned in spite of it and was liable for re-arrest if anyone recognized him and turned him in. He returned for two reasons: first, he wanted to see "his gentleman" Pip; it's revealed that Provis/Magwitch was Pip's benefactor instead of Miss Havisham, as Pip assumed. His second reason was to be avenged on the man (Compeyson) who turned him in originally. Herbert knows that Provis will be arrested and hanged if he's not smuggled out of the country. He is, in fact, caught as Pip is desperately trying to get him to the Continent. Provis is returned to prison but dies before any further punishment can be carried out.
he could be hanged
Pip and Magwitch are going to the coast in order to escape London and potentially leave the country. Magwitch hopes to secure a boat that will take him to a place where he can evade the authorities and start a new life.
Since Magwitch was caught and sent back to prison, it was under the English law that his wealth was to be forfeited to the Crown. That money included the money that made Pip a gentlemen. Pip didn't receive any of it.
Magwitch used the two one-pound notes that Pip had given him to purchase new clothes and supplies to help him evade capture and escape from England.
Magwitch worked for Compeyson, a fellow convict who betrayed him, leading to Magwitch's imprisonment.
Magwitch risks being captured and arrested by going to London to see Pip, as he is a wanted criminal. If he is caught, he will likely be imprisoned or even sentenced to death. Additionally, by revealing his presence to Pip, Magwitch also risks putting Pip in danger of being involved in his criminal activities.
After falling in the river, Magwitch does get sick, but he does not die specifically in prison. He is sentenced to execution by violating expulsion from England. So there for he dies by whatever method they used. I hope that helped :) He actually dies from getting sick. He doesn't get executed.
Abel Magwitch was created in 1861.
In "Great Expectations" by Charles Dickens, Compeyson dies during Magwitch's capture. Compeyson was Magwitch's former partner in crime who betrayed him, leading to Magwitch's arrest and eventual death.