Jeremy supporters like to pretend that Julie had no choice but to confess to various wrongdoings because if she didn't confess to them then police would have found out anyway and Jeremy's lawyers would have used such to destroy her credibility at trial. The myth then continues that Julie was given immunity in exchange for her testimony and that this caused her to lie.
The reality is that there are very limited opportunities at trial to question a witness about prior bad acts and most of those are limited to convictions unless directly related to the case. Even if Jeremy had told the defense lawyers that Julie told him that she had been involved in check fraud he had no way to prove it and all she had to do was deny it. There would be no ability to try to prove at trial that she was involved. Only her confession and that of her friend was able to suffice as proof so unless one of them cracked no one had any way to even try to charge them.
Police didn't know about any of these bad acts until she told them and she told them during the course of ratting Jeremy out. Defense claims that police found out and then confronted her and used such to get her to lie about Jeremy are absurd. These claims totally ignore that police found out only when she was ratting Jeremy out not prior. Moreover, she was not granted immunity they simply decided not to charge her because the only evidence against her came from her and the potential penalties were so minor. If the bank had decided to press charges the most she could have gotten was a fine and low community order.
What crimes did she confess to and why? She confessed to any crimes that she could use to illustrate negative things about Jeremy. 1) she mentioned Jeremy getting her into drugs and having her sell drugs he imported; 2) she mentioned him breaking into the Caravan site as she was with him; 3) she mentioned Jeremy exerted peer pressure to do bad things and thus she decided to do the check fraud. Everything she mentioned was meant to reflect poorly on Jeremy. She didn't confess to things because she had to and for all we know there were more bad things that she could not find a way to tie to Jeremy thus she didn't reveal.
The only one related to the murders in any way is stealing from the caravan site. It is only connected in the limited sense it helps show he was greedy and willing to steal from family and how he trusted Julie. It's the only one she needed to mention to police to illustrate her close position to him and help convince them he was bad. She chose to list the others to try to illustrate even more what her relationship with Jeremy was like. These were not absolutely necessary but it certainly helps make it seem more likely he would confide in her since he enlisted her to sell drugs and go with him to steal from his family. This was her goal in admitting to such. She also gained his trust potentially by telling him about the check fraud and selling drugs for him. It showed not only that he was a bad influence it helped show how she gained his trust.
If she didn't want to try convincing police in such manner she could have chosen to mention none of these things and none of them would have come out in that instance. Police never would have found out about any if she had not mentioned them.
