2A

What do your think they learned from going through Elias’s apartment? Should they have waited for a warrant?

Bosch noticed in Howard Elias’ apartment that the bed had been made which told him that a female was involved as he decided that either he made the bed because there would be someone else in the apartment or someone else made the bed. Bosch felt reasonably sure that there now was another woman in the mix. He found a personal phone book in the drawer of the bed. Many names he recognized but mostly lawyers. There were two toothbrushes in the bathroom. A box of condoms, a girlfriend’s voice on the message of the answering machine. I think they should have waited for a warrant.

Agree with >2 EadieB:
Yes they should wait for the warrant to protect any evidence they may have found to do otherwise is a violation of illegal search and seizure, a protected constitutional right.

He found out a lot of valuable clues but he still should have waited for the warrant.

No warrant could be the downfall of the whole case, no matter how valuable the clues might have been. He knows better than this.