Detectives are using the popularity of the podcast Serial, about the murder of a young girl in Baltimore, as a catalyst for public interest in this unsolved case. They have been releasing clues about the case throughout the last month.
Mike Pimentel was stabbed to death in Liberty Village on New Year's Day 2012.
Pimentel's family made an appeal on Wednesday as police released three new photos showing a man they consider a person of interest. He is described as Caucasian, in his mid-20s, five-foot-six to five-foot-ten with a slim build and short haircut.
Investigators are urging the man, or anyone who knows his identity, to come forward and speak with police.
Earlier this month, detectives Tam Bui and Jeff Tavares began posting clues from the case on Twitter in an effort to crowdsource new information.
Using the hashtag #mikepimentelmurder, Bui has tweeted photos of the crime scene and an image of a woman police hope to identify so they can speak with her. He has also posted photos of three critical pieces of evidence: a hair extension, a high-heeled shoe and a set of keys with a distinctive key chain.
He tweets a new piece of evidence every Saturday, and sent the final clue on New Year's Eve.
"This could be a unique way of drawing information from the general public and more specifically people who were in Liberty Village on January 1, 2012," said Det. Tavares.
Police have also previously released a photo of a knife.
At a police news conference, the mother of Pimentel, Gloria Luz, appealed for tips to find out who murdered her son.
Pimentel was 24 at the time of his death.