Neka is also allegedly involved in smuggling of explosives from Pakistan with the help of Khalistan Zindabad Force (KZF) chief Ranjit Singh Neeta.
While Possi is an original resident of Garh Shanker village in Hoshairpur district, Neka and Cheema belong to Jalandhar district.
Possi has been living in the US for more than a decade and involved in financing terror and motivating Sikh youth against India, Neka and Cheema moved to America after 2006.
All three are in the 30-40 age group.
Although US conveyed its willingness to extradite the terror trio, the Punjab Police has been asked by the ministry of external affairs to move the papers in relevant court in California.
Already the Punjab state government has been informed at the highest levels to push the Jalandhar Range police on case papers and extradition.
The extradition of the three pro-Khalistan terrorist was taken up by top home ministry officials with their American counterparts on the sidelines of India-US strategic dialogue last June with Washington assuring New Delhi that it would help extradite all those living in US and involved in terror acts against India.