A federal jury convicted Dr. Randeep Mann, a naturalized US citizen from India, of using a weapon of mass destruction and destroying a vehicle with an explosive in the February 2009 attack that nearly killed Dr. Trent Pierce.

Mann, a federal firearms dealer, also was convicted of illegally possessing 98 grenades and a machine gun. He was acquitted of illegally possessing a shotgun.

The 52-year-old faces up to life in prison for the weapon of mass destruction charge when he is sentenced on a later date.

Defense attorneys argued investigators targeted the wrong person because of the family physician's race and his love of weapons collecting.

Still, prosecutors argued, there were links, including an e-mail Mann sent to his brother in India with the subject line “Pierce” and a photograph of the doctor, with the text, “I hope this picture is good.” The bomb itself was made from a spare tire from a 2002 Nissan Altima, and prosecutors said a friend and business partner of Mann's had an Altima from which the spare was missing when federal agents executed a search warrant.

Pierce, whose face remains speckled with bits of black tire still lodged in his skin from the bombing, led the panel that sanctioned Mann after complaints he was over-prescribing pain pills to known drug addicts. The board revoked Mann's right to prescribe narcotics after complaints that 10 of his patients overdosed and died.