GRAND RAPIDS, Mich. — A 29-year-old man who shook his 3-month-old son to death will spend at least the next 17.5 years in prison.

"I was supposed to be his protector, his shield and his shelter, but I failed," Matthew Doyle told a Kent County judge ahead of his sentencing Wednesday. 

Read more: Father charged with murder, confessed to shaking infant son

Doyle was first charged with child abuse when his son Sabastian was hospitalized in November of 2018. The boy died days later and Doyle was then charged with murder. 

"I tried to soothe him back to sleep with his pacifier, but he got louder. And I was so tired and groggy from lack of sleep, without thinking I shook my own son" Doyle told the judge. 

Doyle pleaded guilty to the charges in early October. His plea agreement called for a minimum of between 15 and 20 years. Judge Paul J. Denenfeld sentenced him to a maximum of 30 years. 

Sabastian's mother, Chase Thomas, told the judge that Doyle originally lied to everyone involved in the case. Doyle did later admit to police that he shook the boy from side to side and had shaken him an additional time in the weeks prior to his death. Results from a CT scan showed that the baby was bleeding on both sides of his brain. 

Judge Denenfeld said he received an "exceptional" amount of letters from people who were both angry with and sympathetic toward Doyle. 

RELATED VIDEO:

► Emma Nicolas is a multimedia journalist. Have a news tip or question for Emma? Get in touch by email, Facebook or Twitter.

Make it easy to keep up to date with more stories like this. Download the 13 ON YOUR SIDE app now.