Why did Heck Tate and the men accompanying him want Tom Robinson moved out of the local jail?

In the novel To Kill a Mockingbird, Mr. Heck Tate is the sheriff and the reason he wanted to move Tom to the Local jail is because he believed it to be safe from angry whites wanting to lynch him. In those days, it was blacks that mostly occupied the jails, and he realized that because the mobs could not get into the cells to kill Tom, and that there are fellow blacks, that it was safe. I believe that he truly wasn't racist, or as racist as the others.