Problem
Your grandmother, whom you just moved in with, is in her 80s and decides to take a week and go to Vegas to work the casinos. They've got high-stakes bingo in Vegas, who can blame her? While she's away, one of the neighbors notices that her car has been in the driveway for three or four days, that he hasn't seen her weeding the garden every morning like she usually does, and he hasn't heard her usual afternoon TaeBo workouts. He has, however, seen a strange person coming and going (that would be you). He doesn't know that you live there now, so he calls the police to have someone check on your grandmother. The neighbor is troubled by the fact that your grandmother is in her 80s, is usually seen every single day, has never missed a day of gardening and hasn't moved her car in days. Given her age and the fact that she had a heart attack 2 years prior and is on medication for her heart, he fears that she may have died inside the house or been the victim of foul play.
The police show up and knock at the door, but no one answers - you're out for a run. They circle the house walking around to check the place out, knocking on windows and whatnot. All the windows are closed, shades down - they can't see inside except for an answering machine in the kitchen. It says there are 15 messages... They call the house, and there's no answer... so they leave a message. They check the mailbox and there are no other names listed on the mailbox - they see a plastic rock next to the door and sure enough, there's the "Secret Key." Believing that your grandmother may have passed away, broken a hip during TaeBo, or fallen victim to crime, and that she lives alone, they call the ambulance. The ambulance arrives and the police and ambulance crews unlock the door and walk through the house, looking for your possibly injured or deceased grandmother.
They don't find her. They do however, find the baggie of cocaine that your buddy left as payment for you feeding his cat while he was gone. He left it on the coffee table so you couldn't miss it - they didn't miss it either. You walk in from your run right after they find the drugs. Ruh Roh. "That's not mine!"
Are the police allowed to enter your house at all in this case? Don't they need a search warrant? Is it legal for them to invite an ambulance crew in?