Read the HOA Meeting Minutes, the Toxicology Report, and Evidence #8141 (Antifreeze).

The HOA Meeting Minutes show Evelyn thought someone was poisoning the stray cats. The Toxicology Report confirms Evelyn's suspicions — someone was poisoning the cats with ethylene glycol. The picture of the back of the antifreeze bottle shows the antifreeze contained ethylene glycol.

Who did the antifreeze belong to? Examine the grocery list that's pictured alongside the antifreeze for hints. Because the grocery list was thrown out with the antifreeze, we can assume that the person who wrote the list owned the antifreeze.

If you're not sure who wrote the grocery list, read the Saguaro Sands Newsletter. Pay attention to the part about the parade and barbecue.

Also, pay attention to the way the grocery list was written.

The Saguaro Sands Newsletter mentions that Colleen is Saguaro Sands' "resident vegan". The grocery list contains all vegan items, including vegan sources of protein like tempeh and "Beyond Burgers" (imitation meat). The handwriting on the grocery list also matches the handwriting from Colleen's witness statement.

Colleen wrote the grocery list, so the antifreeze is Colleen's.

Examine the Invoice. Pay attention to the address of the purchased property.

Examine the Email Logs. Who is "mildredpierce45@swiftmail.com"?

To figure out who "mildredpierce45@swiftmail.com" is, read the Events Schedule.

Colleen is "mildredpierce45@swiftmail.com".

"Mildred Pierce" is Colleen's favorite movie (see HOA Meeting Minutes), and Colleen recently purchased property near Saguaro Sands (see the Invoice—Colleen purchased property located at 3814 Saguaro Trail. Saguaro Sands is located at 3815 Saguaro Trail.)

Examine the 911 Call Log and pay attention to the phone numbers. Then, review the HOA Meeting Minutes.

The Email Logs reveal Colleen's hidden motive: to buy Saguaro Sands.

The owner of Saguaro Sands, Rosalind, hired SOAR, because they feared Evelyn's murder would go unsolved, residents would leave, and they'd be forced to sell. The Part 1 Introduction letter states "Fear is spreading among the residents—people are leaving, and if this continues, Saguaro Sands will be forced to shut down. Rosalind has asked us to step in and conduct an independent investigation."

Shutting Saguaro Sands down was exactly what Colleen wanted. She’d already bought the land next door (see the Invoice), and now she wanted Saguaro Sands too—so she could expand her property.

Colleen's actions are consistent with this goal. At HOA meetings, she pits residents against each other. She places 911 calls and poses as other residents. She poisoned the stray cats with antifreeze, knowing Evelyn would blame Lorraine. She causes drama so residents will leave Saguaro Sands. Even her move to block the new pool (mentioned in the HOA minutes) is consistent with this. An old, unsafe pool diminishes Saguaro Sands' value, making it cheaper for Colleen to purchase.

But Colleen's ultimate ploy to hurt Saguaro Sands' value was to murder one of its residents. Colleen knew that if the case went unsolved, residents would panic and leave. And she was right—until you caught her.