Jon Wellner (born July 11, 1975) is an American actor, best known for his role as toxicologist Henry Andrews on CSI: Crime Scene Investigation.
He has portrayed Andrews from 2004 through to the 2015 season, his 11th with the show.
[1] He began his affiliation with the show in season 4 as a researcher, verifying that the information on the show was accurate.
He continues to serve as a researcher for the show.
In 2009 he and fellow cast member/researcher David Berman formed a company that does research for several other television forensics shows including Bones, CSI: Miami, and Drop Dead Diva.