Witnesses testifying at the trial of the man accused of killing two teenage girls in Delphi, Ind., were questioned about the so-called "Bridge Guy," seen walking on the hiking trail where the girls were murdered.

Three witnesses who were on the Monon High Bridge trail the day Libby and Abby were killed, including one who said she was best friends with Libby's older sister, testified Tuesday that a man they saw on the trail is "Bridge Guy" — the primary suspect depicted in a grainy photo police later shared to aid their investigation.