After an interdisciplinary investigation involving the Special Victims Unit and the FBI Violent Crimes Task Force, police arrested a man who robbed a couple at gunpoint Tuesday night, then raped the woman as her boyfriend watched."What began as a robbery just totally deteriorated into a sexual assault," said Special Victims Unit Capt. John Darby. "It's just the type of crime itgoes way beyond what a normal person would fathom."An overnight investigation lead the District Attorney to approve charges after police picked up the suspect yesterday evening. The man, 18, is charged with 19 crimes, including rape, robbery, assault, reckless endangerment and related offenses."With thelevel of violence showed and given the information wehave, he was an individual we needed to get off the street rightaway."Police are not releasing the suspect's identity because the investigation is ongoing, "not only related to this incident, but others," Darby said. "We've beenin contact with other investigative divisions to look atother crimes, not necessarily sexual assaults, but crimes of robbery and burglary and thingslike that."Police also continue to look for an accomplice, described as a much younger teen, who participated in the robbery but reportedly begged his friend to stop when the rape began, then fled the scene."My response to that is you werethere, you’re an accomplice," Darby said. "It doesn’t lessen your involvement as far as I’m concerned. So as far as any leniency and sympathy, there shouldn’t be.""There were twoparties that were involved here and they put these two folks in fear of their lives."Cops cooperateDarby emphasized the importance of collaborating with different types of law enforcement. "We worked very closely in a cooperative, coordinated effort with people at various levels," Darby said."But this wasn't a single, one-time effort. Working with local, state and federal-level investigatorsis commonplace. It happens here at SVU every day.""The public needs to know and it should givethem some level of comfort that we can’t prevent – in all cases – these types of crimes, butwe are certainly going to go after the offenders in a very aggressive way, not only at local levels.""The results here are an excellent example of what you can get– the arrest of the perp with the gun ho committed the sexual assault.""Horrific situation"@font-face {font-family: "Times";}@font-face {font-family: "Cambria";}p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.storyintro, li.storyintro, div.storyintro { margin: 0in 0in 0.0001pt; font-size: 10pt; font-family: "Times New Roman"; }span.storydateline { }div.Section1 { page: Section1; }"This was a nasty job, really bad," Darby said. "When I talk about anincident being egregious or over-the-top, this is what I mean."The couple was attacked Tuesday night as they walked home from dinner.Aman approached them around 48th Street and Baltimore Avenue between 9:30 and 10 p.m. brandishinga handgun and demanded they walk to anisolated, overgrown area at the rear of the 4700 block of Springfield Avenue.Waiting for them there was the accomplice, who helped to pat the two down and steal items.The first man, angry and unsatisfied with the robbery proceeds, began to rape the female, at which point the accomplice fled. "Clearly, one man was more aggressive than the other," Darby said."Agun's being placed to her head, to his head. are pleadingfor the individuals to stop, saying, 'Look, you robbed us and you tookour money, go ahead and go.'"But instead, the man continued to sexually assault the woman while forcing her boyfriend to watch.Neither victim suffered serious physical injuries, though both are reportedly attempting to recover from mental trauma.Police are focusing their efforts on apprehending the accomplice. "Rightnow, we’re developing information regarding the second teen," Darbysaid."Suffice to say, we are aggressively pursuing getting thataccomplice identified."