The Los Angeles police chief and district attorney have released a letter defending their exhibit of evidence from famous crimes.

The letter was issued Friday after the son of Robert F. Kennedy denounced them in a Los Angeles Times op-ed piece for planning to show the suit the senator wore when he was assassinated. Maxwell Kennedy called it "a macabre publicity stunt."

Chief Charlie Beck and District Attorney Steve Cooley say they never intended to compound the grief of murder victims' families. Beck and Cooley say they sought to depict the horror of homicide in hopes of deterring violence.

Thursday was the last day the exhibit was open to the public at a Las Vegas casino hotel. Police say thousands have waited in line as long as two hours to see it.