American Marconi Wireless News - Man questioned in case of murdered health exec: US media 

The man was quizzed by police in Altoona, Pennsylvania, after being found with a distinctive weapon like that used in the brazen shooting of Brian Thompson, NBC News and others reported citing sources familiar with the case.

Police have been looking into the possibility that the shooter used a long-barrel veterinary gun -- normally used to euthanize animals -- to commit the murder.

The gunman walked up behind Thompson, a senior figure at UnitedHealthcare -- one of the country's largest medical insurers -- and shot him dead last Wednesday in front of bystanders, in an attack captured by a surveillance camera and since seen by millions.

Thompson was attending an investor conference in the Midtown business district.

Police have yet to suggest a motive and would not confirm media reports that the words "delay" and "deny" -- language often used by insurance companies to reject claims -- were written on shell casings found at the scene.

Video footage shows Thompson on the sidewalk outside the New York Hilton Midtown when a man in a hooded top, his lower face covered, approaches from behind, then fires several shots at his 50-year-old victim, who crumples to the ground.

The New York Police Department told AFP that detectives had no update for the media, while the Altoona Police Department did not respond to requests for comment.

P.Stevenson--AMWN