I like listening to podcasts as I go on my walks.
True Crime All the Time is quite good. It can be a bit slow sometimes but the banter between the hosts helps to make a very dark topic less depressing.
http://www.truecrimeallthetime.com/
True Crime Historian is ok. It is someone just reading old newspapers stories about murders.
http://truecrimehistorian.com/
When you've listened to enough of these podcasts you'll end up praying for the return of capital punishment.