St. Paul police are asking for the public's help in identifying the armed suspects in three recent home invasion robberies.

It's unclear if the robberies are related and whether they were targeted or random, but their timing and proximity to each other on the city's East Side is alarming, police said.

"Our homicide/robbery unit is working diligently to determine whether these cases are connected, to identify the suspects and to find them," said police spokesman Steve Linders. "It's bad enough that people are out there robbing others, but it's even worse when they're breaking into people's homes and violating their sense of security."

The incidents occurred between Feb. 11 and early Wednesday.

According to the police: On Feb. 11, officers were called to a home in the 1400 block of Hazel Street about 7:20 p.m. The 62-year-old male homeowner told police that when he arrived home that night, he saw a man walking nearby. The homeowner parked in his garage. When he exited the garage, a male suspect pointed a black handgun at his head and ordered him inside his home, where his 62-year-old wife was.

The lone suspect ordered the couple to sit on their couch, Linders said. He demanded money and also threatened them. At one point, the suspect took the couple downstairs where he had the man lie face down. He tied the man's hands behind his back with a vacuum cord. The suspect eventually untied him and brought the couple back upstairs.

The suspect rifled through drawers in the home, ordered the couple to wait 10 minutes before doing anything and then fled with some cash in the homeowner's Ford Fusion, Linders said.

The suspect is described as a black male, six-feet tall, slender and wearing a gray sweatshirt, gray sweatpants and a black mask.

The second incident occurred on Feb. 16 just before 7 p.m. in the 2000 block of 4th Street E. A 31-year-old man at the home told police that he stepped outside to smoke a cigarette when a man pointed a handgun at his head and ordered him to look away and re-enter the home.

The lone suspect asked where the money and guns were, Linders said. He took $400 in cash from the male victim. There were also three other adults ranging in age from 24 to 27 in the home, along with an undetermined number of children.

"He threatened the children," said Linders, who could not elaborate on what those threats entailed.

The suspect ordered the male resident into a bedroom and took a gun. The suspect eventually ordered everyone to lay on the floor and then fled.

The suspect was described as a black male, 6-foot to 6-foot-2, slender and wearing a black sweater, dark pants, dark shoes and a white glove on his right hand.

The third incident occurred about 2:40 a.m. Wednesday at an apartment building in the 800 block of Maryland Avenue East. A 36-year-old man and 26-year-old woman were asleep when three men entered their apartment.

One suspect, armed with a gun, woke up the victims and demanded money and guns, Linders said. The male victim said he had no guns. The armed suspect and a second man took money from the couple, flipped their mattress over and fled with the third male suspect, who had been waiting in the kitchen.

It's unclear if the second or third suspects had guns, and what type of gun the first suspect had in his possession, Linders said.

The armed suspect in the third robbery is described as a black male in his early 30s, bald and wearing a red hooded sweatshirt.

Home invasion robberies account for a very small number of the approximately 300,000 calls St. Paul police respond to each year, Linders said.

"Home invasions are very unusual," he said. "…this is concerning, because we've seen three in the last couple of weeks."

Anyone with information can call police at 651-266-5650.

Chao Xiong • 612-270-4708

Twitter: @ChaoStrib