harassment from Sherrifs

What is the name of your state? Missouri

Is harassment fom law enforcement legal? How much is too much.
My oldest daughter is 18 yrs old. Her and one of her friends were here at my house while I was out of town one day. When I arrived home I noticed that I was missing a good amount of my vicoden. I didn't say anything until the next morning when my husband said that some of his percocet were missing. I then went to my daughters house and asked for our pills back even though I highly doughbted that it was her because none of my medication has ever been missing. She knew nothing about them being gone. One of her other friends said that the girl that was at my house with my daughter was well known around town for stealing drugs and giving them to her Mom. I went home and told my husband and he went to the sheriffs dept. to report this. They went to this other girls house and recovered some of the medication. We were told by a friend in the police dept that the girl and her family would have had plenty of time to get rid of some of the pills and make up a good story. And that they did. They said that my daughter had been distributing them. So, for about 2 months now, my daughter and all her friends are being followed, searched and her friends arrested. They have never found anything on my daughter or in her posession except some marajauna seeds. A few of her friends have had more pot and other law problems, so they are in jail. But, because of what the first girl said (the one who actually stole my meds), my daughter is being followed around the clock everyday. Every where she goes, they search houses and cars. What can be done to stop this?