Columbo, the series, was created to normalize police harassment as the police's only investigative technique, by showing you the murder first to pretend they only harass the right guy, and at a more basic level to pretend that there was any investigation at all when too much of the public was becoming aware that the only method the police still used was picking the nearest person from a minority and beating a false confession out of him, "third-degree interrogation", decades after the Wickersham Commission's https://en.wikipedia.org/wiki/Wickersham_Commission#Findings
"Report on Lawlessness in Law Enforcement". By contrast, Japan openly uses "hostage justice" 人質司法 (ひとじちしほう) as its only investigative technique in the vast majority of cases, whereby a suspect is kept indefinitely in pre-indictment detention, in fixed periods that are invariably renewed, without lawyers present during questioning, until he confesses https://www.hrw.org/news/2019/04/10/call-eliminate-japans-hostage-justice-system-japanese-legal-professionals
regardless of guilt. So Columbo, the detective, wouldn't even be needed for Yagami.
However, in a fictional Japan that eliminated "hostage justice", there is an episode of Columbo, the series, that provides the answer to OP's question. It's an early one with the psychologist using his patient to provide him with an alibi after murdering his wife, by dressing up as his wife and acting out a scene with him at the airport. Columbo repeatedly admits that he has no way of getting him on the evidence, he can only get him through her, and the evidence also supports this without needing Columbo to admit to it. Columbo gets the doc to say that he has no feelings for the naive patient and was going to arrange her death if she ever started making demands or blackmailing him. She is secretly listening and at that point agrees to testify against him.
So the doc is sociopathic enough to commit cold-blooded, calculated murder and to use her as a tool, but not sociopathic enough to kill her preemptively to close any avenue of getting to him. In the equivalent scenario, being untouchable on the evidence and never cracking himself, Yagami would have no problem with preemptive murder to close any avenue of getting to him. Therefore in the equivalent scenario Columbo would lose.