Baltimore County police arrested an 18-year-old man in connection with Monday's triple shooting at a Catonsville motel that left a man dead.County police on Tuesday identified the suspect as Jose Diaz-Contrenas.Police said officers were called early Monday to the Motel 6 in Catonsville, where they found three shooting victims."At 3 a.m., our officers responded to the 5800 block of Baltimore National Pike for a reported shooting," Baltimore County police Sgt. Gladys Brown told 11 News on Monday. "We have a suspect in custody in reference to that incident."Javier Argueta, 30, died at the scene, and paramedics took two other men, 19 and 25, to hospitals with what appeared to be non-life-threatening injuries, police said. Diaz-Contrenas was charged with first-degree murder and two counts of attempted murder, police said on Tuesday.Based on the investigation, police said this was an isolated incident. Diaz-Contrenas remains held at the Baltimore County Detention Center without bond.Some motel guests told 11 News they had just fallen asleep when they heard gunshots. One man told 11 News he woke up to what sounded like five shots. He said he left his room to see what happened and saw two men on the hallway floor. He said what he saw startled him.According to charging documents, officers found Dias-Contrenas walking around the parking lot of the motel. Surveillance video obtained by officers shows a suspect pulling a handgun from under his jacket and firing several rounds at the victims.Court records also indicate that he admitted to the shooting, and stated that "he could not stop" and kept shooting at the victims.Investigators did not immediately release information on what may have led to the gunfire, saying that is part of the investigation."Right now, our officers are working hard to piece the events together to understand why this incident occurred," Brown said.Diaz-Contrenas is scheduled to return to court for a hearing on June 23. Anyone with information is asked to call police at 410-307-2020 or Metro Crime Stoppers at 866-7LOCKUP.A Motel 6 representative sent a statement to 11 News, saying: "Our thoughts are with the family and loved ones of the victims, and we are doing everything we can to assist law enforcement with their investigation. There is nothing more important to us than the safety of our guests, hotel employees and the communities in which we operate, which is why we have invested hundreds of millions across all aspects of the business, including a wide variety of safety programs, over the past decade."