Mouse Murderer

So this morning I was walking down the stairs and I thought what I saw was a clump of hair (gross I know, but I live with four other girls and there are hair balls frequently in the washing machine etc.). When I looked a little closer, I realized it was a mouse, but it looked like a fake mouse so I thought one of my roommates was playing a joke. I looked really closely at it for about 2 minutes and it didn't move, so I assumed it was fake, and decided since I wasn't scared enough for the prank to be worth it to whomever pulled it, I would leave their mouse there for another roommate to be terrified of, which I'm sure would have happened. An hour or so later I heard a loud rustling in my bedroom. I looked over, and sitting next to a toiletry case, and a sweatshirt that was on the ground, was the mouse! So what did I do? I put a plastic bag on my hand, walked over to him and grabbed him. He tried to run away into the sleeve of my sweatshirt on the ground, but I grabbed his tail and pulled him out by it. I was surprisingly calm and serene while all of this was going on. I went to take him out to my backyard to let him live out the remainder of his mouse days, but then I realized, he got in here somehow, whats to stop him from vacationing at the Casa de Alyssa again? So I made the decision to throw him (think baseball pitcher) into the irrigation ditch that runs right next to my house. So unless mice can swim in relatively fast moving canals, I am now a mouse murderer.