Plan your crime; you can't have a crime caper novel without one. Your crime should include an extremely valuable prize protected by impenetrable security (high tech bank vault, super secret papers hidden in a 60 room mansion, an industrial secret shielded by laser beams and tripwires). Don't forget to figure out how your heroes will pull the caper off.
Research the details; it doesn't matter how imaginative your caper is, if readers don't believe it, they won't buy it. Look into all of the peripheral details involved in pulling off the crime: vault security, surveillance systems, high-tech burglary tools, escape vehicles and weapons. The more detail you can offer your reader, the more believable the caper will become.
Flesh out your team (crime capers rarely involve a single hero). Start with your team leader, who must be something of a rogue himself; he can be a disgraced cop or security expert, a famous burglar forced out of retirement, a former special services vet forced to hire on from desperation. The secondary team members must bring key specialties to the job, whether it be surveillance skills, computer and electronic wizardry, safe cracking or high speed driving.
Target your mark. Marks take two forms, an institution such as a bank with high tech security, or a well-heeled and high profile personality (you can even combine the two to create a person who happens to own the high tech facility). You should create a connection or history between the team leader and the mark: he could have been a former employee of the facility or the mark is not married to his ex-wife. The mark should have some weakness that the team can exploit to pull off the caper.
Outline your book. Set up the caper as quickly as possible and make sure to build a back story explaining the relationship between the team leader and the mark and his connection to team members (he should have a history with at least one of them). Don't include any more back story than is absolutely necessary; it can interfere with the story. But make sure the team leader has more at stake than just the heist.
Throw in at least one complication to throw the caper into jeopardy (one of the team members could have a secret grudge against the team leader or could be willing to sell the entire team out, a new security system has been installed at the last minute or one of the team members could get arrested). The complication may be a real obstacle the team has to overcome or yet another diversion to sidetrack the mark.
Sleep on your outline. Give yourself a week or two off so you can return fresh and then look for holes in the plot and character contradictions that need to be resolved.