Vladimir Putin has ordered Russian police to put a stop to political killings.

“We must rid Russia for good of the shame and the tragedies like the one we witnessed recently. I am referring, of course, to the shocking murder of Boris Nemtsov right in the heart of the capital,” Putin said.

Putin also demanded a “radical breakthrough” in Russia’s crime-solving rate. “In 2015, we need to improve our efforts in all key areas, and we must especially raise the number of crimes solved—those recent and from years past,” Putin said.

Boris Nemtsov was murdered in Moscow on February 27. Putin personally tasked the heads of the Investigative Committee, the Ministry of Internal Affairs, and the Federal Security Service with managing the investigation into the homicide.

Police have failed to make any arrests in the case, so far, and they have yet to release any details about the progress of their investigation. On March 4, when asked if there are any suspects in the case, Federal Security Service head Alexander Bortnikov said, “There are always suspects.”