From his bio, Gaspipe, written by Philip Carlo.

I know this has been covered in another thread, but here's a quick summary, as per Casso...

Castellano assigned the job to murder DeMeo to Gotti. Gotti was unsuccessful and recommended to Big Paul that they use Gaspipe. Paul agreed. Gaspipe's strategy was to recruit the Testa brothers and Anthony Senter. The reward for the Testas was they were going to be made into the Lucchese family. Senter was not 100% Italian.

DeMeo went to Patty Testa's home to collect money and was clipped there. The body was put in the trunk of his car and Anthony Testa drove it to Varras Boat Club in Sheepshead Bay, where his body was discovered a week later.