Who is Pamela Starr Madden from Without Remorse and what is their importance?

Pam witnessed her friend Helen's murder and was later picked up while hitchhiking by John Kelly. Pam is from Texas, and she is also a Quaalude addict. Raised in a strict household, she suffered numerous beatings at the hands of her father. A runaway, she spent time in Houston before heading for New Orleans, where she became a prostitute. She was later sold to Henry Tucker who used her to run drugs. In the end, Pam is killed by Billy and his drug people. Kelly seeks revenge.