An ex-EMT admitted he took a gruesome cellphone pic of a Staten Island murder victim while on duty and posted it online.

Mark Musarella, 47, pleaded guilty yesterday to official misconduct and disorderly conduct for snapping the photo of strangling victim Caroline Wimmer and putting it on Facebook.

Musarella, who was assigned to Richmond University Medical Center, must complete 200 hours of community service and is banned from working as an EMT.