Complex sentence: Witnesses later reported that Harris seemed disoriented--possibly from the heavily bleeding wound to his nose.Harris taunted Pasquale, Klebold noted Ireland trying to provide aid to Hall, who had suffered a wound to his knee.
Split into simpler sentences: Witnesses later reported that Harris seemed disoriented--possibly from the heavily bleeding wound to his face. As Harris taunted Pasquale, Klebold noted Ireland trying to provide aid to Hall, who had suffered a wound to his knee.