SALEM – A Superior Court jury acquitted a Lynn man charged with slashing a 31-year-old ex-girlfriend in the face during a home invasion in 2006.Bernard Robinson, 38, who last lived at 34 Broad St., #6, in Lynn, went on trial this week in Salem Superior Court on charges of mayhem, house invasion and assault and battery with a dangerous weapon.A jury comprised of eight women and four men deliberated for about three hours Friday, returning a not guilty verdict on all three charges.Prosecutors accused Robinson of forcibly entering his former girlfriend’s home at 4 Kenwood Terrace on the night of Oct. 14, 2006 and slashing her across the face with a sharp object, causing a 4-inch laceration.The alleged victim, now 32, took the stand and told the jury that she had been dating Robinson for about six years on and off, but had broken up with him a month before.Robinson’s attorney William J. O’Hare maintained his client was innocent, did not do the things charged and had an alibi. He said was with other people that night, who testified corroborating his story.O’Hare argued that the victim was not credible and for whatever reason accused Robinson of the crime.Robinson did not take the stand in his own defense.He was indicted by an Essex County grand jury in December 2006 and has been held in custody in lieu of bail since.