They are re-showing the detective series Luther on BBC America. I noticed that they gave it an hour, which includes 15 minutes of commercials, for a running time of 45 minutes. I then looked at downloads of Luther to see how long the actual running time is, and it is 53 minutes. So they have to cut out 8 full minutes of the story to get it into an hour. This is just program butchery. Taking 8 minutes out of a detective program makes the story line incomprehensible, since too much is missing. I cannot understand how this can be allowed. .
I don't know about Luther and the mystery genre but most BBC hour-long documentaries have an actual running time of 58 to 59 minutes. Thus, when shown in an hour block by a US commercial network such as the Science Channel, substantial elements of the program presumably must be cut to permit insertion of advertisements.