Shane Finnegan was the lead singer of the famous, fictional, boy band Channel Street Boys, and a childhood friend of Jane and Frankie Rizzoli.
Growing up with the Rizzoli siblings, he was very close with Frankie, even wanting to form a band with him, and had a crush on Jane, even writing the band's hit song "Pure Boston Beauty" about her, who once told Shane that he could sing.
Shane, Ronan and Liam were all exploited by their father, Ryan, who made them form their band and used his position as their manager and using up all their money for his own gains. Once they were old enough, they sent their father to jail and continued their rise in the music industry as Channel Street Boys.
At one point during his career, he got involved with drugs. While in rehab, he meets famous pop singer Gia Lemond and later becomes romantically involved with her. They have both committed to staying away from drugs and, eventually, decide to run away together.
When Shane's brother, Ronan, finds out that Shane is quitting the band to go to Port-au-Prince, Haiti with Gia, he talks a reluctant Liam into a pact of killing their brother and use his death for publicity. They later kill him, with Ronan delivering the killing shots.
Jane, Frankie and Angela, all close to Shane as a child, were all heartbroken to hear the news. Gia later presumably commits suicide with overdose of drugs after hearing the news.