Generally speaking, the police either need your permission or a warrant to search through your personal property – but there are some important exceptions.
One very important thing to keep in mind is that anything you discard is largely “fair game” for the authorities to grab.
There’s no reasonable expectation of privacy over your trash
The 4th Amendment of the U.S. Constitution guarantees everybody a reasonable expectation of privacy over whatever they have on their person, places of business and inside their homes – but trash is effectively surrendered as soon as you throw it in a public bin or put your can out on the curb for collection.
In those situations, not only do the police not need a warrant to rifle through what they find, they don’t even need a reason (probable cause) – mere curiosity is enough.
Something isn’t trash until it actually leaves your possession
All that being said, it’s also important to understand where the authorities are limited in this power.
They cannot, for example, take an empty paper cup out of your hand if you aren’t willing to hand it over. Nor can they take trash from what’s considered the curtilage of your home – which could include the bins you have behind a privacy fence or the ones set right next to your garage.
Lately, there have been some significant breakthroughs in the use of genetic evidence to solve cold cases – and forensic genealogy is an emerging science that’s growing in importance all the time. That’s likely to make the question of “what is” and “what is not” trash a much bigger legal issue in the future.
If you’re facing serious criminal charges and genetic evidence is involved, make sure you have experienced legal guidance.