CLEARWATER — The foster grandmother of a baby fatally attacked by a family dog last October will not face criminal charges.

Authorities were investigating whether criminal negligence contributed to the death of 7-month-old Khloe Williams while Pamela Maser was babysitting the infant. After the attack, Pamela Maser called her son and her husband rather than 911.

The Pinellas-Pasco State Attorney's Office decided this month not to pursue a charge of aggravated neglect of a child against Maser.

"There must be a willful, wanton disregard for what's going on, and you simply don't find that here," State Attorney Bernie McCabe said in an interview.

PREVIOUS COVERAGE: Clearwater police: Dog fatally attacks 7-month-old baby girl

The Pinellas-Pasco Medical Examiner's Office also released Khloe's autopsy report this week. The report concluded that she had bleeding in the brain as well as sharp-force wounds, scratches and bruises all over her body. A medical examiner told prosecutors that she died from asphyxiation after blood and other fluids pooled her lungs, according to a State Attorney's Office internal memo.

Khloe had been living since May with Maser's son, Jonathan, and daughter-in-law, Melissa, after the baby was removed from her birth mother, Shavon Grossman. Jonathan Maser works as a detective for the Clearwater Police Department, the same agency that investigated the dog attack. Paul Maser is a former deputy chief of the department and now works part-time reviewing records.

About 1:45 p.m. Oct. 5, a caseworker dropped Khloe off at Pamela Maser's house at 1125 Fairwood Ave. following a visit with Grossman. Jonathan Maser, his wife, Melissa, and two of the couple's children went to see a movie about six miles away at the AMC Woodlands Square 20 in Oldsmar.

The baby started crying, so Pamela Maser prepared a bottle. The dog, a retriever-hound mix named Josie, started barking in her kennel. The grandmother opened the kennel to let the dog outside.

Instead, the dog went straight for Khloe, who was sitting, unstrapped, in a car seat on the couch. Pamela Maser pried the dog off the girl and put the dog outside. Khloe was taken to Mease Countryside Hospital and pronounced dead. Pinellas County Animal Services later euthanized the dog.

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An internal memo spelled out why prosecutors decided not to charge Pamela Maser. The decision to let the dog out of the kennel with Khloe close by was "an incredibly poor decision," the memo said. But family members said the dog was loving, so there was no reason to believe she would become viscous.

The delay in calling 911 also gave prosecutors pause. Pamela Maser said in an interview with detectives that she didn't initially realize the extent of the child's injuries, according to Clearwater police documents released this week. She called her son and husband and asked them to come home immediately, telling them the dog had attacked Khloe. Prosecutors noted in the memo that Pamela Maser had "minimized the child's injuries when she called family members asking for help."

The first phone call to her son was at 1:50 p.m. He and his wife left the theater a minute later, according to surveillance video noted in the Clearwater police reports. They arrived home soon after 2 p.m. to a situation more dire than they expected. Pamela Maser — "white as a ghost," Jonathan told detectives — told her son and daughter-in-law she thought Khloe had died.

The child had grown cool and quiet in her arms.

Jonathan Maser called 911 at 2:08 p.m. His wife performed CPR while they waited for help. Paramedics arrived about eight minutes later.

Clearwater police detectives told prosecutors they had probable cause to arrest Pamela Maser on a child neglect charge because she didn't call 911 while she waited for her son to arrive, according to the prosecutors' memo. An emergency room doctor, though, said the child was dead at the house.

"The child might have likely died even if the defendant had called 911 right away," the' memo says. "We won't be able to prove beyond a reasonable doubt that the defendant's failure to call 911 resulted in death."

Kevin Hayslett, a lawyer for Pamela Maser, said his client was in shock and thought her husband and son, who both have law enforcement experience, were better equipped to handle the situation.

"There are a lot of things that anybody would do differently with the knowledge they had in the future," Hayslett said.

Nioti Koulianos, a lawyer for birth mother Grossman, repeated questions raised earlier about whether the investigation was impartial — questions that police Chief Dan Slaughter said were baseless.

Koulianos initially called for the Florida Department of Law Enforcement to step in because of the Maser family's ties to Clearwater police.

But Koulianos said he doesn't plan to challenge the state attorney's decision.

"It is what it is. We didn't harp on it," he said. "We didn't make a big deal about it, and we don't plan on it because we're not out for revenge."

Contact Kathryn Varn at kvarn@tampabay.com or (727) 893-8913. Follow @kathrynvarn.