PENNSYLVANIA – Police are questioning a man in Altoona, Pennsylvania, in connection with the fatal shooting nearly a week ago of a top US health care executive on a busy New York City street, two law enforcement officials familiar with the matter tell CNN. Working off of a tip, police stopped a person traveling by bus and recovered a suppressor – a device that muffles the sound of a firearm – and a number of false IDs, one official added. That man is now in custody and being questioned.

The development comes amid an intense search for whoever fatally shot UnitedHealthcare CEO Brian Thompson. Authorities have known what the suspect looks like but not who or where he is. Through glimpses of his unmasked face, his movements through the country’s largest city and the belongings police say he discarded, he seems almost familiar but remains a mystery.

The public, too, has seen the suspect in surveillance photos and videos – including one with him pointing the weapon at Thompson’s back – and as he continues to evade capture in the December 4 killing outside a Midtown Manhattan hotel. The suspect was believed to have left New York City on an interstate bus, police officials said, after video cameras captured him entering the George Washington Bridge Bus Station on 178th Street but not leaving. (CNN)