Michelle Macnamara had nothing to do with the guys identification and capture, that's true. She wouldn't have found him either, he was never going to end up on a suspect list to be investigated.
However, she had a lot of details right (his profile and background) and she was dead on with how he would caught. She may not have been a part of the "investigative team" officially, but her relationship with them was important. She's very much responsible for bringing attention to the case, which was very much needed, and appreciated by the team. DeAngelo flew under the radar compared to other notorious serial killers due to his career of crime being credited to multiple monikers. The Visalia Ransacker (which wasn't confirmed until capture), the East Area/Side Rapist, and the Original Night Stalker. The last two weren't connected until the end of last century.
Being able to attribute all of DeAngelos crimes under one name gave the case the attention it deserves. That's probably her greatest contribution.
Yes, it's disingenuous to say that Michelle brought down the Golden State Killer, but it's also disingenuous to say that she didn't contribute at all. The method that caught him had been discussed as a possibility long before it happened, she was definitely aware of that. Basically, she was an online crime sleuth that was good enough to become a trusted ally and contributor to the investigation.
B-b-but guys, he said he was really sorry about it.
/barf
The feeble old man shit these people do is so rich. I remember watching this documentary on one of the later Nazi trials and the Nazi fuck pulled the same shit. Yet he was obviously fine. No one buys it, you pigs.
And of course he was a cop. ACAB forever.
With how much his fragile masculinity ate him up, that was only job that would suit him, unfortunately.