WolfSinger Publications has several anthology calls posted for this year. There are two that are of special interest here:
"Love 'em, Shoot 'em" is looking for stories of 1000 to 6000 words that use the theme "I ain't afraid to love a man. I ain't afraid to shoot him either." This is open to a variety of genres which include Western and Mystery. The deadline is June 30, 2016 and payment is a $5 advance plus royalties. You can find the details here.
The second is "Incarceration". The stories must feature incarceration in the future and while they're looking for speculative fiction this is a good one for mixing in crime fiction. Stories should be 1000 to 6000 words. The deadline is August 31, 2016 and payment is $5 plus royalties. You can find the details here.