can my eployer keep my last paycheck if they are accusing me of a crime ?

Generally, an employer must pay whatever they owe an employee (1) immediately if it fires the employee or (2) within 72 hours after the employee quits working for the employer.  (Labor Code Section 201(a).)  Failure to do so will potentially subject the employer to waiting time penalties pursuant to Labor Code Section 203.  However, there is authority in the Wage Orders promulgated by the Industrial Welfare Commission that allows an employer to deduct from your wages any amounts attributable to conduct ranging from gross negligence to theft.  The burden of proof is on the employer to prove that, and, if can't sustain that burden, it will probably be liable for waiting time penalties.  Having said that, if the amount that's in dispute is less than your paycheck, your employer should've paid you the difference.  If you want to contest this, you can file a claim with the Labor Commissioner or file a civil suit for your wages.  (Because the amount at issue seems to be small, filing a claim with the Labor Commisioner would probably be best.)  Of course, if you do decide to institute legal proceedings of any kind with respect to your wage claim, you may have to testify and therefore waive any an opportunity to invoke the Fifth Amendment privilege in any later matter (e.g., a criminal trial).  Before you decide to do anything, you might want to figure out the criminal angle first.  It's one thing to get stiffed on wages,  but it's quite another thing to face criminal charges.