Occurring from the mid-1970s to 1981, the Ripper committed 13 murders. Viewed as ritualistic in nature, they were done with extreme brutality as he mocked the police during their desperate hunt for him. The victims were primiarly prostitutes or poor girls, with a few working girls tossed in. Generally he would hit a victim on the head with a hammer, sexually assault the lady, mutilate her, and then redress/re-arrangement the clothing and cover the corpse with her own coat. .