El arte de morir (2000)

In Spain a young artist has gone missing, and a hardened detective takes on the case. Six friends become the focus of the investigation, being pressured for their knowledge of the artist's whereabouts. They all deny involvement, and soon they have reason to fear for their lives as it appears a serial killer is hunting them all down. The one friend closest to the artist watches helplessly as his once quiet life is shattered by incrimination, suspicion and ultimately -- horrific violence.