I have just signed a new lease. The leasing agent says they countersign my lease after I move in. I still have a few days before I move in. Is this common/legal? Does it not expose the lessee to some risk?
In any legal dealing, there is always some risk. The signature constitutes definitive proof that you have a contract, but you still have a contract, because you have mutual acceptance. A far-fetched scenario is that the lessor could allege that they did not agree to the terms of he contract with you (perhaps claiming that you obtained a blank contract form from them and filled in details, but they didn't agree to those details). However, if they allow you to move in, that is sufficient constructive evidence of a contract, so they could not argue "We didn't agree to this". The main risk would be your lack of proof that they ever agreed to lease the place to you (no emails, no texts, no witnesses, no legally-recorded conversations). There may be specific state laws about providing a copy of the rental agreement, such as this California law, where they must provide a copy to the tenant within 15 days of execution by the tenant. This provides a collection of relevant state laws, though you may have to dig a bit because this is a hook into all of the laws about leases and not just about providing copies.