The public relations mogul was shot multiple times while driving her Mercedes-Benz car through Los Angeles on her way home from the premiere of Cher and Christina Aguilera's new film Burlesque last week (16Nov10).
Family, friends and clients of Chasen, including T-Bone Burnett, Diane Warren and Hans Zimmer, turned out for her funeral at Hillside Memorial Park in Culver City, California on Sunday, and Cohen remembered his sibling in a moving eulogy.
He told the mourners how they played together as children and he often carried his sister home from the movie theatre on his back, ending the speech by calling Chasen "my little companion".
Chasen's client and longtime friend Zimmer also paid tribute to the PR ace and emotionally declared: "My heart is broken."
She was later buried in a private service in front of family and close friends.
Police so far have no leads as they investigate Chasen's death, and rewards totalling $125,000 (£83,300) have been offered for information leading to the killer's conviction.