[4] Born in Woodbury, New Jersey, Knapp grew up in Northern California and graduated from Franklin High School in Stockton,[3] where he was the senior class president.

[2][5] At KLAS-TV, Knapp has served a number of roles, including as a news anchor, a member of the I-Team investigative unit, as well as the host of "Street Talk".

[6] In 1991, Knapp left KLAS to work for Altamira Communications, a public relations firm whose clients included advocates of the Yucca Mountain nuclear waste repository 90 miles (140 km) north of Las Vegas.

Founded by Las Vegas businessman Robert Bigelow, NIDS was charged with scientifically studying unusual phenomena with scientists and funding.

Based on his work with NIDS deputy administrator Colm Kelleher, Knapp publicized the so-called Skinwalker Ranch in northeast Utah, where strange events are alleged to have occurred.

[14] Knapp has been credited for introducing Nevada senator Harry Reid to Robert Bigelow because of their shared interest in unidentified aerial phenomena.

[17] According to skeptical writer Mick West, "George Knapp was (and still is) very much a believer in aliens, having built a considerable segment of his career in promoting the claims of Area 51 confabulator Bob Lazar as factual".

[2][10] Knapp and photojournalist Matt Adams were recognized for their work on the investigative series Crossfire: Water, Power, and Politics that received a 2008 Peabody Award.