LOUISVILLE, Ky. (WDRB) -- WDRB is discovering how good, old-fashioned police work and today's medicine came together to make an arrest in a cold case murder. By looking at the case file, a doctor today was able to determine that a toddler was murdered, 42 years ago.

The murder happened in 1971, right around the time that Shaken Baby Syndrome was first being discovered and described in the world of medicine. At the time, doctors could not definitively say that the child's injuries weren't accidental.

Michael Sanders would be 44-years-old, if he were alive, but police say he was murdered at just 20-months-old in 1971.

"Like any toddler who's physically assaulted and ultimately died, he most certainly suffered, and he did not die a quick and painless death, unfortunately," said Dr. Melissa Currie, medical director in chief of the Kosair Charities division of pediatric forensic medicine.

"We know a lot about bruising patterns in children now that we didn't know back in the 70s," said Currie.

Investigators often use Currie's expertise as a child abuse pediatrician to determine if bruising on a child is from an accident or abuse. LMPD recently called Currie to look at Michael Sanders' case.

"From what I can gather from the autopsy, he ultimately bled to death," said Currie.

Detectives in the 1970s had a prime suspect: the boyfriend of the child's mother, Lawrence Beck.

"The detectives who did the leg work on this case were well ahead of their time," Currie explained. "They did a fantastic job documenting in detail what the boyfriend had described happened, the timeline, all of those kind of things."

Doctors in the 70s believed the child was abused, but couldn't completely dispute Beck's stories that Michael had fallen and that his injuries were accidental.

"The doctors at that time did not have the kind of data they needed to be able to say to a reasonable degree of medical certainty that a typical childhood shortfall couldn't have caused these injuries, we know now certainly it cannot," Currie explained.

Dr. Currie could determine today what doctors in the 70s could not: that Michael Sanders was violently assaulted.

Now Beck is charged with murder.

"While it would've been better for Michael to never have died to begin with, it's definitely a good feeling to know I was able to play a part in getting justice for him," said Currie.

WDRB spoke to one of the original detectives in the case, who does not want to talk about the case until it is over in court.

Beck is in jail at Metro Corrections on a $500,000 full cash bond. He declined an interview.

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