WILMINGTON, Del. — Jurors in Hunter Biden’s gun trial began deliberating Monday after they heard new evidence from a witness about his drug use in October 2018, around the time he is alleged to have illegally purchased a firearm. 

Prosecutors rested their case after they told jurors that Biden was a “habitual” user of drugs from 2015 to 2019, a period that overlaps with his gun possession, and that he knew he was an addict and even wrote extensively about it in his memoir. 

His lead…