Step 1: Make a new document size 400 x 100, then add a black to white gradient across it: Preview

Step2: Go to Filter >> Distort >> ZigZag, then use these settings: Amount = 100 Ridges = 20 Style = Pond ripples You should get something that looks like this: Preview

Step 3: Go to filter >> Distort >> Wave, select square, then click randomize, you should get something that looks like this: Preview

Step 4: Go to Filter >> Noise >> Add noise, have amount set at 13.13, distribution = Uniform, and check Monochromatic. You should get something that looks like this: Preview

Step 5: Go to Filter >> Blur >> Radial Blur, select zoom and have Amount = 100. You can choose the quality yourself. You should get something that looks like: Preview

Step 6: Go to Filter >> Brush Strokes >> Ink Outlines, and use the settings: Stroke Length = 4 Dark intensity = 20 Light intensity = 10 Click OK and you should get something like this: Preview

Step 7: Go to Image >> Adjustments >> Hue/Saturation, check colourize then mess around until you get the red colour you like, you should end up with this: and there you have it, an effective looking blood splatter, try experimenting to see what you can come up with: Preview

My final picture turned out like Preview