HIGHLAND PARK, Mich. -

A cold case in Highland Park has been solved thanks to one woman’s vow never to give up.

Melissa Kountz witnessed the murder of her cousin, Andrew Weathers, in 1983 when she was just 13 years old. Willie Lyles Jr. was immediately named a suspect but was never arrested. 

The case was put on the backburner. However, in 2007, Kountz contacted the Highland Park police and persuaded a detective to reopened the case. 

Police eventually found Lyles this past summer in Oak Park and arrested him.

"Finally, after 29 years, a horrible monster has finally been convicted and justice has been served,” said Kountz. "This case was more about the life of the victim ... "

Lyles was recently sentenced to life in prison.