Jim and Kim wanted to get a van with a mattress in the back, so they could be by themselves whenever they wanted to. However, Jim's affluent father refused to loan Jim the money to pay for the van. So, Jim came to the conclusion that the only way he and Kim could get the money to pay for the van was to break inside of his home, steal his father's valuables, and re-sell them to a guy he knew who would pay for the valuables in cash. Jim wasn't worried about causing his parents any financial damage because they were well insured. The only problem was that his father kept the room where the valuables were stored locked. His father also kept the key to the room on his person all the time, therefore making it impossible for Jim to steal it when he was sleeping (as Kim had originally suggested.) Jim was aware that Edward had a special ability to pick locks without leaving a scratch after he assisted Jim and Kim by getting into Kim's house by picking the lock. And naturally, he knew Edward would be the perfect person to help him get into his father's house, undetected, without leaving any evidence that he was around. Jim wanted Kim to ask Edward to participate in the break-in because he knew that Edward would say yes because Edward had a crush on Kim. Much to Jim's frustration, Kim felt reluctant to ask because she didn't think it was fair to take advantage of Edward. To appease her boyfriend, Kim eventually asked Edward, however she didn't tell him who's house they were breaking into or why they were doing it. Edward agreed, just as Jim had predicted.
Jim later, lied to Edward by telling him they were breaking into the house of somebody who stole from him. However, Edward secretly knew that it was Jim's house all along and later revealed to Kim that the only reason why he went along with it was because she asked him to. It also explained why Edward didn't snitch on Kim or Jim, not wanting Kim to get into trouble.
When an unexpected alarm is tripped, locking Edward into the room with the stored valuables, everyone flees. Kim didn't want to abandon Edward, not wanting him to be involved in the first place. Jim forced Kim to leave because he knew that his father would prosecute against him, but not against Edward whom Jim had gotten off the hook by lying to his father and telling him that Edward was mentally incompetent and could not understand what he was doing. This is corroborated by the psychiatric evaluation on Edward after a psychiatrist discloses to Edward's arresting officer, Officer Allen, that Edward cannot differentiate between right and wrong, so Edward was ultimately released from jail, but would've stayed in longer, had Jim not said anything. Jim couldn't have cared less about Edward and his predicament, as he had threatened to kill Edward if he told, but got him off, in order to placate Kim.