Solving crimes is what most people believe the Police should be doing. Murder is, of course, the worst crime and occupies its' own classification in the Illinois Criminal Code.
His only option is to question as many people as possible, to believe those who deserve belief, and to be a good judge of what he hears. - Polyibus, The Histories Book 12 Chapter 4c
Unfortunately, over the past 40 years the clearance rate for homicides has steadily dropped. From a high of about 75% solving a murder is now a 50/50 shot. Now, this is bad in the aggregate but, it might not be as bad as the data and graphs seem to illustrate.
Because for a long time clearance rate was simply based on the making of an arrest and unfortunately old school Police tactics were unethical and borderline criminal, besides the outright heinous crimes of the infamous Chicago Officer John Burge.
I'm not going to say solving a murder is ever "easy", but departments do have a wider array of diagnostic kits, greater investigative tools, and superior evidence collection at their disposal than ever before. But, the most important aspect of investigating crimes remains face-to-face investigations. Known for a long time as "shoe leather" detective work. Have investigation skills, interview techniques, attention to details, critical thinking lapsed since the old days? I doubt it. The dismal clearance rate for murder is instead a direct reflection of a lack of trust of Police Officers and Departments by society.
Due to constant bad actions (and I don't mean just spectacular crimes like Chauvin's) and the proliferation of information Police Departments have also lost moral authority. Because of this people know who is responsible for many murders they just don't want to tell Police the information.
That's bad and it strikes at the core problem facing Policing going forward and right now. #3 of Sir Robert Peel's nearly 200 year old 9 principles of Policing; The police must secure the willing cooperation of the public in voluntary observance of the law to be able to secure and maintain public respect. Those 9 maxims still stand as basic guidelines for Policing in the United States and Western liberal Democracies.
Can Police get the trust and cooperation of society back? Not now. I don't know what it will take to regain trust. If it is even possible. Defund? Reformation? Police reform has been a catch-phrase and running theme for decades. Police reform is only accomplished when a new generation with a new way of thinking takes over and the problem with Policing was identified by Raymond Chandler a century ago; 
