When was there ample time for the killing?

Hint 1 of 12:

Okay, first off all, you better find some evidence first before trying to
determine this.

Hint 2 of 12:

If you've done this, you'll know that one person had a motive for killing
Robner (Baxter), and another had medicine which killed him (Dunbar).

Hint 3 of 12:

First off, analyze that fragment in the backyard for LoBlo and get the lab
report.

Hint 4 of 12:

Show the report to Dunbar and she'll get itchy.

Hint 5 of 12:

Accuse her (save first!).