TAMPA (AP) – A veteran Tampa police officer was gunned down by a man who once served as a police officer in the U.S. Virgin Islands, Tampa Police Chief Steve Hogue said Thursday.

Cpl. Mike Roberts, 38, was shot once Wednesday night after confronting and struggling with a man who was seen pushing a shopping cart full of items along the street in a high-crime area of the city, Tampa police said. Roberts was wearing body armor, but the slug went through his right arm and into a part of his chest unprotected by the vest.

The suspected shooter, Humberto Delgado Jr., 34, was tracked by a police dog and arrested a short time later. Hogue said Delgado was a police officer in the U.S. Virgin Islands from 1996 to 2000.

Hogue said Delgado was armed with three handguns and an assault rifle. He said Delgado pulled the rifle from a canvas bag in the shopping cart and pointed it at another officer who came to Roberts’ aid.

“The truth is, as tragic as this situation is, we’re probably lucky there were not additional police officers shot and hurt last night,” Hogue said at a Thursday news conference.

Receipts in Delgado’s wallet indicate he bought the guns at a pawn shop at Fort Bragg, N.C., in 2008, Hogue said.

Tampa Mayor Pam Iorio recalled talking to Roberts about his family at a ceremony in July during which he was promoted to corporal.

“That’s all he talked about was his 3-year-old son,” Iorio told reporters shortly after the shooting. “He was the best, and that’s what we lost tonight.”

Police said Roberts approached Delgado on the street just before 10 p.m. Wednesday. Roberts struggled with Delgado, who broke free and ran.

When Roberts caught up on the other side of the street, Delgado pulled out a handgun and pistol-whipped him before shooting him once, police said. Roberts was pronounced dead at a hospital at 10:50 p.m.

Roberts is survived by a wife and 3-year-old son. He won a lifesaving award in 2005 and had served with the U.S. Air Force and Army. His personnel file contains dozens of letters of appreciation from citizens, supervisors and other law enforcement agencies.

Delgado, who has no prior criminal record in Florida, is charged with first-degree murder of a law enforcement officer and other crimes. He is being held and has not yet appeared in court. Documents do not list an attorney.

A U.S. Virgin Islands police spokeswoman did not return a call seeking information about Delgado’s tenure at the department.

A Facebook page belonging to a Humberto Delgado Jr. whose birth date matches the one provided for the shooting suspect, said he attended high school in St. Croix, one of the Virgin Islands. He lists his employer as the Department of Veterans Affairs, but a VA spokeswoman said he has never worked for the agency.

Delgado served in the Army for about 15 months in 2004 and 2005, according to an Army spokesman. Citing privacy regulations, the spokesman wouldn’t disclose the conditions of Delgado’s discharge.

A woman who said she was Delgado’s cousin told Bay News 9 that he recently moved to the Tampa area and was living on the streets after moving out of his uncle’s house in Oldsmar, northwest of Tampa. She said he had a history of mental illness.

Under the “About Me” heading on Facebook, Delgado wrote: “Just here on earth trying to survive in this world without loosing (sic) my identity.”