Letter By Sean Phillips States Baby Kate is Dead

A major development in the Baby Kate case — a letter, believed to be written by Sean Phillips, details how his daughter died.

It's a story 9&10 News has followed every step of the way — since Baby Kate disappeared in Ludington in late June of 2011.

Just yesterday, we told you that Ariel Courtland filed papers to marry Sean Phillips, who's in prison.

Today, Evan Dean obtained a letter — allegedly written by Phillips — detailing how his daughter died.

Baby Kate was just four months old at the time she was last seen.

Phillips was convicted of secret confinement in April of this year, and was sentenced to at least ten years in prison.

Now the shocking letter, written for Baby Kate's mom, Ariel Courtland, has surfaced.

The source who gave our news team a copy of the five-page letter did not want to be identified.

But they say the letter was postmarked on July 16th — believed to be written in prison by Sean Phillips, and addressed from Sean to Ariel Courtland.

It offers some shocking insight into the day Baby Kate went missing — stating that the infant is dead — but that it was all just an accident.

It says Sean didn't realize the infant was still in his car when driving away from Ariel's apartment that day.

The letter states that he was angry at Ariel, and thought she left the empty baby seat in his car on purpose — so he'd return to her.

It says he was going to throw it out into an area near Burger King.

“I pulled but it was jammed between the seats. That just made it worse. I grabbed it at the top and ripped it out as hard as I could. She was thrown from it. I didn't know. I'm so sorry. Held her for a long time. Seemed like forever.”

The letter says Sean then drove away — regretting not trying to help the baby.

It says he kept driving until eventually getting out of the car to walk around, holding Kate.

It doesn't say where he was, but reads, “I cried until I couldn't anymore. She was set in a peaceful place. I was walking and lost… Then I was driving. For the first time I realized I had left her. I wanted to die.”

As for the potential marriage between Sean and Ariel… Ariel's family says in light of the new letter, they think it may be so she doesn't have to testify against Sean.

We sat down with April Lange, Ariel's mother & Baby Kate's grandmother, who says she considers the letter a relief — if the death was an accident.

But she's outraged Sean didn't try to get help.

“In the letter he said I never had a chance to make it right. He had plenty of chances it right. He could have said something at any time, he could have told the truth,” April said.

As much information as the letter may offer, it still doesn't answer the biggest question of all — where is Baby Kate?

Police say they've know about the letter for weeks, and are using it to further their murder investigation of Sean Phillips.

They aren't yet calling it a confession.

“The letter helps our investigation, but it's another part of the investigation. There are other leads that we're following up on. Other avenues of the investigation that are being pursued. This is just part of it,” said Paul Spaniola, the Mason County Prosecutor.

9&10's Evan Dean and Photojournalist Jake Johnson tracked down the letter today and have the story.

We've also attached the full five-page letter, believed to be written by Sean to Ariel.