SALEM – Blake Colella, the 25-year-old Swampscott native currently serving 7-to-10 years in prison for stabbing a Lynn man outside a 7-Eleven two years ago, got another two years and probation slapped onto his punishment Thursday after confessing to assault, narcotics and witness intimidation charges in Superior Court.Colella, who last lived at an apartment at 69 Lynnway, in Lynn, pleaded guilty to two additional cases pending against him, but refused to admit to a third case involving the alleged beating of his girlfriend last year, saying he wants a trial.He pleaded guilty to charges of possession with the intent to distribute heroin, distribution of heroin within a school zone, two counts of assault with a dangerous weapon, two counts of threatening to commit the crime to kill, two counts of threatening to blow up homes and two counts of intimidation of a witness.Judge David A. Lowy sentenced Colella to serve two years in state prison, followed by two years of probation when he gets out, with special conditions he stay away from the victims and receive drug treatment and counseling as deemed necessary with random substance abuse screenings.This prison term will not commence until he completes the 7-to-10-year sentence he is now serving for the 2006 stabbing of a Lynn man.In essence, Colella probably will serve at least 10 years in prison before he is eligible for parole, given his past violent and criminal record going back to his teens.Assistant District Attorney Michael P. Hickey said he would have established at trial that on Sept. 17, 2006, Colella intimidated two female witnesses, a Swampscott and a Salem woman, with a handgun in his Parkland Avenue apartment, where he was living at the time. He took them to the basement area of the building, where he threatened to shoot them both if they testified against him at his upcoming trial for stabbing the Lynn man outside the 7-Eleven Store at 264 Essex St., in May 2006. The women had previously told authorities they helped Colella get his car from the parking lot.Colella told the women that the gun was loaded and had hollow tip bullets, but when authorities seized the handgun, they found it to be inoperable.The women were at his Parkland Avenue residence for several hours before they managed to leave the property unharmed, Hickey said.Then three days later on Sept. 20, as they tried to distance themselves from Colella, they received threatening calls from him saying he would shoot them or blow up their respected homes if they testified against him. The girls then went to Swampscott police and reported the incidents.On the night of Feb. 3, 2007, while out on bail, Colella was arrested in Lynn at a Stop & Shop parking lot on Boston Street after being caught with more than nine grams of heroin. Another packet of heroin was also found on his person during booking.He was arrested about 50 yards from the O’Keefe Alternative School, according to Hickey.In asking the judge to adopt the sentence agreement, defense lawyer Lawrence J. McGuire said that the agreement reached was the result of a great deal of conferences. He said that Colella will be in his mid 30s when he gets out of prison and that he hopes that he takes advantage of programs available to him while incarcerated.The judge agreed to credit Colella the time he has spent in jail awaiting trial on the two cases.The remaining charges still pending against Colella concern the June 13 and June 21, 2007 beating of his 21-year-old ex-girlfriend. He allegedly punched her in the eye and slapped her in the face numerous times at his 69 Lynnway #5 apartment. Then on June 25 she told police he beat her again and tried to strangle her with a cell phone charger cord and with his bare hands. He also struck her with a set of keys.The ex-girlfriend told authorities that Colella had been physically assaulting her at his Lynnway apartment during their two-month relationship – allegations he denies.That case was continued to March 27 for tri