Experts Doubt Donald Trump's Plan to Execute Cop Killers Would Pass Muster

“Our police officers have been treated horribly,” he told ABC News.

“Our police officers have been treated horribly,” Trump told ABC News aboard his private jumbo jet Wednesday. “They've been tremendous supporters of me. … I have great, great feelings for the police of this country. They do a great job and, yes, I want the death penalty for anybody that kills a police officer."

Pressed on how he would accomplish it, Trump said he would "work with the states if I have to; if we can do it on a federal basis, we’ll do it on a federal basis.”

Trump previously raised the issue in the same week he proposed a controversial temporary ban on Muslim Americans entering the United States.

Some legal experts are skeptical.

“I really question if he could do something like that,” professor Deborah Denno of the Fordham University School of Law in New said. “There have been only 37 federal executions since 1927.”

Indeed, according to a report released Wednesday by the Death Penalty Information Center, "The national trend towards abolition of the death penalty in law or practice continued: Nebraska legislatively abolished the death penalty; the Connecticut Supreme Court declared its death penalty unconstitutional; and Pennsylvania joined three other states in imposing gubernatorial moratoria on executions.”

“Putting the death penalty part aside, given the Supreme Court’s relaxed commerce clause when it comes to federal criminal law, I suppose such a federal offense could be created if there is, say, a nexus between the gun used in the crime and interstate commerce."