Nel Apgar

From Memory Alpha, the free Star Trek reference.

Doctor Nel Apgar was a Tanugan scientist.

In 2366, he developed a Krieger wave converter in his orbiting research station above Tanuga IV. The research was supported by the Federation and Will Riker visited him to check on his progress. Apgar concealed the discovery from Riker because he decided to sell the Krieger wave as a weapon. Apgar attitude plus his request for extra material so he could complete the weapon caused Riker to become suspicious of Apgar's intentions. Fearing he might be exposed, Apgar decided to kill Riker. As Riker was transporting back aboard the Enterprise, Apgar fired a Krieger wave at him, but the beam was reflected back into the station's main reactor by the transporter beam surrounding Riker and Apgar was killed when the station exploded. (TNG: "A Matter of Perspective")

Dr. Apgar was played by actor Mark Margolis.